Compositions and methods for prophylaxis and treatment of addictions

ABSTRACT

The present invention relates to methods of treating or preventing addiction and relapse use of addictive agents, and treating or preventing addictive or compulsive behavior and relapse practice of an addictive behavior or compulsion, by administering a peroxisome proliferator-activated receptor gamma (PPARγ) agonist, alone or in combination with another therapeutic agent, such as, for example, an opioid receptor antagonist or an antidepressant, or an addictive agent, such as, for example, an opioid agonist. The present invention also includes pharmaceutical compositions for treating or preventing addiction or relapse that include a PPARγ agonist and one or more other therapeutic or addictive agents, as well as unit dosage forms of such pharmaceutical compositions, which contain a dosage effective in treating or preventing addiction or relapse. The methods and compositions of the invention are useful in the treatment or prevention of addiction to any agent, including alcohol, nicotine, marijuana, cocaine, and amphetamines, as well as compulsive and addictive behaviors, including pathological gambling and pathological overeating.

CROSS-REFERENCE(S) TO RELATED APPLICATION(S)

This application is a continuation of copending U.S. patent applicationSer. No. 13/853,585 filed Mar. 29, 2013, which is a continuation of U.S.patent application Ser. No. 12/722,429 filed Mar. 11, 2010, which is acontinuation-in-part of U.S. patent application Ser. No. 12/101,943,filed Apr. 11, 2008, now pending, priority from the filing dates ofwhich is hereby claimed under 35 U.S.C. § 120, and claims the benefitunder 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No.60/911,201 filed Apr. 11, 2007; U.S. Provisional Patent Application No.61/159,377 filed Mar. 11, 2009; and U.S. Provisional Patent ApplicationNo. 61/167,824 filed Apr. 8, 2009, where these (three) provisionalapplication are incorporated herein by reference in their entireties.

BACKGROUND Technical Field

The present invention is directed generally to the treatment orprevention of addictions using PPARγ agonists, alone or in combinationwith other therapeutic agents.

Description of the Related Art

The World Health Organization (WHO) defines substance addiction as usinga substance repeatedly, despite knowing and experiencing harmfuleffects. Substance addiction is a chronic, relapsing diseasecharacterized by a loss of control over drug use, compulsive drugseeking and craving for a substance, use that persists despite negativeconsequences, and physical and/or psychological dependence on thesubstance. Substance addiction typically follows a course of tolerance,withdrawal, compulsive drug taking behaviour, drug seeking behaviour,and relapse. Substance abuse and addiction are public health issues withsignificant social and economic impact on both the addict and society byplaying a major role in violent crime and the spread of infectiousdiseases. Addictive substances include alcohol, caffeine, nicotine,cannabis (marijuana) and cannabis derivatives, opiates and othermorphine-like opioid agonists such as heroin, phencyclidine andphencyclidine-like compounds, sedative ipnotics such as benzodiazepinesand barbiturates and psychostimulants such as cocaine, amphetamines andamphetamine-related drugs such as dextroamphetamine andmethylamphetamine.

Alcohol is one of the most commonly abused substances at a global level.Additionally, alcoholism leads to serious liver and cardiovasculardisease and generates dependence resulting in severe mental disorders,social problems and adverse consequences including the division offamilies, tragic accidents and the reduction of work performance.According to the WHO, alcohol consumption is responsible for 20-30% ofoesophageal and liver cancer, liver cirrhosis, homicides, epilepsy, andmotor vehicle accidents worldwide. Globally, alcohol abuse leads toabout 1.8 million deaths per year. Compulsive behaviour towards theconsumption of alcohol is a core symptom of the disorder. In recentyears several approaches have been investigated to help alcoholicpatients to not only control alcohol drinking but also alcohol cravingsand relapse (Monti et al., 1993; Volpicelli et al. 1992; O'Brien et al.1997).

Medications such as naltrexone, acamprosate, ondansetron, disulfiram,gamma hydroxybutyrate (GHB), and topiramate tested for their potentialtherapeutic effect on alcohol abuse belong to several classes(Volpicelli et al. 1992; O'Brien et al. 1997). Few of thesepharmacotherapeutics, such as naltrexone, acamprosate, and disulfiram,have been proven to be of a certain utility and approved for thetreatment of alcoholism. Among these medications, the non-selectiveopioid antagonist naltrexone is currently considered the pharmacologicalgold standard. However, despite some promising results none of thesemedications, including naltrexone, is of sufficient efficacy inalcoholism and prognosis remains poor.

Nicotine is one of the most widely used addictive drugs, and nicotineabuse is the most common form of substance abuse. The WHO estimates thatthere are 1.25 billion smokers worldwide, representing one third of theglobal population over the age of 15. The WHO further estimates that 5million deaths occur each year as a direct result of tobacco use, makingnicotine abuse the largest single preventable cause of death worldwide.In industrialized countries, 70-90% of lung cancer, 56-80% of chronicrespiratory disease, and 22% of cardiovascular disease instances areattributed to nicotine addiction. Cigarette smoking is associated with430,000 deaths a year in the US alone and is estimated to cost thenation 80 billion dollars yearly in health care costs. Tobacco useaccounts for one third of all cancers, including cancer of the lung,mouth, pharynx, larynx, esophagus, cervix, kidney, ureter, and bladder.The overall rates of death from cancer are twice as high among smokersas among nonsmokers. Smoking also causes lung diseases such as chronicbronchitis and emphysema; exacerbates asthma symptoms; and increases therisk of heart disease, including stroke, heart attack, vascular disease,and aneurysm. An estimated 20% of the deaths from heart disease areattributable to smoking. Expectant women who smoke are at greater riskthan nonsmokers for premature delivery, spontaneous abortion, andinfants with decreased birth weight.

Nicotine use results in increased levels of the neurotransmitterdopamine, which activates the reward pathways to regulate feelings ofpleasure and to mediate the desire to consume nicotine. Symptomsassociated with nicotine withdrawal include craving, irritability,anger, hostility, aggression, fatigue, depression, and cognitiveimpairment, which lead the abuser to seek more nicotine. Environmentalconditioning factors and exposure to psychological stress representadditional factors motivating nicotine use in smokers. Repeated nicotineuse results in the development of tolerance, requiring higher doses ofnicotine to produce the same initial stimulation.

Most therapies developed for nicotine addiction have shown only moderatesuccess in preventing relapse, leading to a high failure rate inattempts to quit smoking. Treatments include the use of nicotinereplacement products, anti-depressants, anti-hypersensitives, andbehavioural therapy.

The National Institute on Drug Abuse estimates that 72 millionAmericans, about one third of the population, have tried marijuana.Acute effects of marijuana use include memory and learning problems,distorted perception, difficulty problem solving, loss of coordination,and increased heart rate. Long term abuse can cause the same respiratoryproblems observed in tobacco smokers, such as daily cough, phlegmproduction, increased risk of lung infections, and an increased chanceof developing cancer of the head, neck and lungs. Depression, anxiety,and job-related problems have been associated with marijuana use. Longterm marijuana use can result in addiction with compulsive use thatinterferes with daily activities. Cravings and withdrawal symptoms, suchas irritability, increased aggression, sleeplessness, and anxiety makeit difficult for addicts to stop using marijuana. There are nopharmaceutical treatments available for treating marijuana addiction andrelapse.

According to the WHO, an estimated 13 million people abuse opiatesworldwide, including 9 million heroin addicts. More than 25% of opiateabusers die from suicide, homicide, or an infectious disease, such asHIV and hepatitis, within 10-20 years of becoming addicted. Toleranceand physical dependence can develop within two to three days. Whileabuse and addiction to opioid agents is a known phenomenon, what is newis the worsening of this problem in the recent years (Compton and Volkow2006; Compton and Volkow 2006). Epidemiological surveys of youth in theUnited States in 2003 indicated that opioid analgesics were among themost frequently abused illicit drugs among secondary students (12thgraders), second only to marijuana (Delva et al. 2005). Furthermore, thepast few years have seen a marked increase in the use of opioidmedications in the United States and an even greater increase inproblems associated with such use. This upsurge in use and problems isparticularly concerning because it seems to represent an expandedpathway to opioid addiction (Siegal, Carlson et al. 2003).

According to recent epidemiological data, 4.7% (i.e., 11.0 million)United States household residents over the age of twelve abused anopioid medication in 2002 and 13.7% of these persons (i.e., 1.5 million)endorsed the symptoms of a DSM-IV opioid use disorder (Association 1994;Substance Abuse and Mental Health Services Administration 2004). Asrecently reviewed by Compton and Volkow, the annual incidence of opioidanalgesic abuse increased from 628,000 initiates in 1990 to 2.4 millioninitiates in 2001 (Administration 2003; Substance Abuse and MentalHealth Services Administration 2003). One of the reasons fostering theexpansion of opioid addiction is the increased use of analgesicsecondary to medical prescription. Short term use of opioid medicationis rarely associated with addiction. Conversely, protracted treatmentswith these agents have been associated with development of addiction inup to 18% of patients.

The goals for treatment of opiate addiction, as with other types ofsubstance addictions, are to discontinue the use of the opiate whileminimizing painful withdrawal symptoms and preventing relapse. Currenttreatments involve replacing the addictive drug with a substitution ofan opioid receptor agonist or mixed agonist/antagonist. An alternativeapproach consists of the use of an opioid receptor antagonist to blockthe effect of the agonist. Antagonists provide no relief from pain orother withdrawal symptoms; rather, they can precipitate withdrawal, andtheir therapeutic use was associated with increased accidental opioidagonists overdosing and increased lethality. Use of agonists with alower affinity for the receptors results in the least severe withdrawalsymptoms, but it can lead to a dependence on the substitute opiate.Also, many substitution therapies take 3-6 months, allowing time foraddicts to stop treatment midway.

Psychostimulants, such as cocaine and amphetamines, cause euphoria,increased alertness, and increased physical capacity in humans. Thesesubstances first increase dopamine transmission, but long term drugusage results in a reduction of dopamine activity, leading todysregulation of the brain reward system and dysporia. The WHO estimates33 million people around the world abuse amphetamines.

Chronic cocaine abuse can result in hyperstimulation, tachycardia,hypertension, mydriasis, muscle twitching, sleeplessness, extremenervousness, hallucinations, paranoia, aggressive behaviour, anddepression. Cocaine overdose may lead to tremors, convulsions, delirium,and death resulting from heart arrhythmias and cardiovascular failure.Desipramine, amantadine and bromocriptine have been shown to decreasecocaine withdrawal symptoms.

Amphetamine withdrawal symptoms include EEG changes, fatigue, and mentaldepression. Tolerance develops over time and may be associated withtachycardia, auditory and visual hallucinations, delusions, anxietyreactions, paranoid psychosis, exhaustion, confusion, memory loss, andprolonged depression with suicidal tendencies. Current treatments foramphetamine addiction include phenothiazines, haloperidol, andchlorpromazine for hallucinations, but potential side effects of thesedrugs include postural hypotension and severe extrapyramidal motordisorders.

In the past, treatment for substance addictions focused on behaviouraltherapy, but dependence on many of these highly addictive substances ishard to break. In particular, addictions to alcohol, cocaine, and heroinare considered chronic, relapsing disorders. Also, concurrent abuse ofmultiple substances, such as nicotine, heroin, cocaine and alcohol, iscommon.

The long-lasting, chronic nature of many addictions and high rates ofrecidivism present a considerable challenge for the treatment of drugand alcohol addiction, such that understanding of the neurobiologicalbasis of relapse has emerged as a central issue in addiction research.Emotional and environmental factors (conditioning stimuli) were listedamong the main causes of relapse. For example, it is known that specificstress conditions such as loss of work and economic difficulties, orstimuli predictive of the presence of alcohol previously associated withits use such as a bottle of the preferred wine and a bar-likeenvironment, may strongly facilitate relapse in detoxified formeralcoholics.

Two major theoretical positions exist to explain the persistence ofaddictive behaviour and vulnerability to relapse associated with drugand alcohol addiction, homeostatic hypotheses and conditioninghypotheses.

Homeostatic hypotheses relate relapse risk to neuroadaptive changes anddisruption of neuroendocrine homeostasis that are thought to underlieanxiety, mood dysregulation and somatic symptoms that accompany acutewithdrawal, and that can persist for considerable periods of time duringwhat has been referred to as the “protracted withdrawal” phase. Thisview, therefore, implicates alleviation of discomfort and negativeaffect as a motivational basis for relapse.

Conditioning hypotheses are based on observations that relapse is oftenassociated with exposure to drug-related environmental stimuli. Thisview holds that specific environmental stimuli that have becomeassociated with the rewarding actions of a drug by means of classicalconditioning can elicit subjective states that trigger resumption ofdrug use. The homeostatic and conditioning hypotheses are not mutuallyexclusive. In fact, homeostatic and conditioning factors are likely toexert additive effects in that exposure to drug-related environmentalstimuli may augment vulnerability to relapse conveyed by homeostaticdisturbances.

Clearly, there is a need in the art for new methods for treating andpreventing addiction and the relapse use of addictive agents. Thepresent invention meets these needs by providing methods andpharmaceutical combinations useful in treating and preventing addictionand recidivism.

BRIEF SUMMARY

The present invention is directed generally to the use of PPARγagonists, alone or in combination with one or more additionaltherapeutic agents, for the treatment and prevention of addictions andrelapse to addictive use or behavior. Accordingly, the present inventionprovides methods and related compositions, unit dosage forms, and kitsuseful for the treatment and prevention of addictions, and for thetreatment and prevention of relapse use of addictive agents or practiceof addictive or compulsive behaviours.

In one embodiment, the present invention includes a method of treatingor preventing an addiction, comprising determining that a subject has oris at risk of developing an addiction, and providing to the subject anamount of an agonist of a peroxisome proliferator-activated receptorgamma (PPARγ agonist) effective for the treatment or prevention of theaddiction.

In a related embodiment, the present invention provides a method oftreating or preventing an addiction, comprising providing to a subjecthaving an addiction a peroxisome proliferator-activated receptor gamma(PPARγ agonist) and an additional therapeutic agent, wherein each of thePPARγ agonist and the additional therapeutic agent contribute to theeffective treatment or prevention of the addiction.

In certain embodiments of the methods of treating or preventingaddiction of the present invention, the PPARγ agonist is athiazolidinedione (TZD). In particular embodiments, the TZD ispioglitazone, rosiglitazone, ciglitazone, troglitazone, englitazone,rivoglitazone, or darglidazone. In certain embodiments, the additionaltherapeutic agent is an opioid antagonist, a mixed opioid partialagonist/antagonist, an antidepressant, an antiepileptic, an antiemetic,a corticotrophin-releasing factor-1 (CRF-1) receptor antagonist, aselective serotonin-3 (5-HT3) antagonist, a 5-HT_(2A/2C) antagonist, ora cannabinoid-1 (CB1) receptor antagonist. In particular embodiments,the opioid antagonist is naltrexone or nalmefene. In particularembodiments, the antidepressant is fluoxetine, mirtazapine, orbupropion. In particular embodiments, the antiepileptic is topiramate,levetiracetam, or gabapentin. In one embodiment, the CRF-1 receptorantagonist is antalarmin. In another embodiment, the selectiveserotonin-3 (5-HT3) antagonist is ondansetron. In particularembodiments, the cannabinoid-1 (CB1) receptor antagonist is rimonabantor tanarabant. In one embodiment, the mixed opioid agonist/antagonist isbuprenorphine.

In certain embodiments of the methods of the present invention, thesubject is addicted to an addictive agent, or at risk for relapse use ofan addictive agent. In particular embodiments, the addictive agent isalcohol, nicotine, marijuana, a marijuana derivative, an opioid agonist,a benzodiazepine, a barbiturate, or a psychostimulant. In certainembodiments, the opioid agonist is selected from the group consistingof: morphine, methadone, fentanyl, sufentanil and heroin. In certainembodiments, the psychostimulant is cocaine, amphetamine or anamphetamine derivative. In addition, the subject may be addicted to morethan one addictive agent, and the pharmaceutical compositions, unitdosage forms, and kits may be useful for treating or preventingaddiction or relapse use of more than one addictive agent.

In other embodiments of the present invention, the subject is addictedto an addictive or compulsive behavior or at risk for relapse practiceof an addictive or compulsive behaviour. In particular embodiments, theaddictive or compulsive behavior is pathological gambling, pathologicalovereating, pathological use of electronic devices, pathological use ofelectronic video games, pathological use of electronic communicationdevices, pathological use of cellular telephones, addiction topornography, sex addiction, obsessive compulsive disorder, compulsivespending, anorexia, bulimia, intermittent explosive disorder,kleptomania, pyromania, trichotillomania, compulsive overexercising, andcompulsive overworking. In addition, the subject may be addicted to morethan one addictive or compulsive behaviour, and the pharmaceuticalcompositions, unit dosage forms, and kits may be useful for treating orpreventing addiction or relapse use of more than one addictive orcompulsive behaviour.

In particular embodiments of any of the methods of the presentinvention, the addictive agent is alcohol and the additional therapeuticagent is an opioid antagonist or a mixed opioid antagonist/partialagonist. In one embodiment, the opioid antagonist is naltrexone. Inanother embodiment, the mixed opioid partial agonist/antagonist isbuprenorphine.

In other particular embodiments of any of the methods of the presentinvention, the addictive agent is nicotine and the additionaltherapeutic agent is an antidepressant. In one embodiment, theantidepressant is bupropion.

In further particular embodiments of any of the methods of the presentinvention, the addictive agent is a psychostimulant and the additionaltherapeutic agent is an antidepressant. In one embodiment, theantidepressant is bupropion.

In other particular embodiments of any of the present invention, thesubject is addicted to two or more addictive agents and the additionaltherapeutic agent is an opioid antagonist or a mixed opioid partialagonist/antagonist. In certain embodiments, the opioid antagonist isnaltrexone or nalmefene. In other embodiments, the mixed opioid partialagonist/antagonist is buprenorphine.

In further related embodiments, the present invention provides a methodof preventing relapse use of an addictive agent or practice of anaddictive or compulsive behaviour, comprising providing an effectiveamount of a peroxisome proliferator-activated receptor gamma (PPARγagonist) to a subject who has undergone a period of abstinence from, orlimited or reduced use of, the addictive agent or practice of theaddictive or compulsive behaviour. In certain embodiments, the subjecthas undergone physiological withdrawal from the addictive agent duringthe period of abstinence from, or limited or reduced use of, theaddictive agent or due to no longer being exposed to an effective amountof the anti-addiction treatment. The anti-addiction treatment may be ananti-addiction drug or may be a non-pharmacologic therapy such ascounseling, psychotherapy or hypnosis therapy.

In a related embodiment, the present invention includes a method ofpreventing relapse use of an addictive agent or practice of an addictiveor compulsive behaviour, comprising providing an effective amount of aperoxisome proliferator-activated receptor gamma (PPARγ agonist) to asubject who has undergone a period of abstinence from, or limited orreduced use of, the addictive agent or practice of the addictive orcompulsive behaviour, and also providing to the subject an additionaltherapeutic agent, wherein each of the PPARγ agonist and the additionaltherapeutic agent contribute to the effective prevention of the relapseuse or practice. In certain embodiments, the subject has undergonephysiological withdrawal from the addictive agent during the period ofabstinence from, or limited or reduced use of, the addictive agent ordue to no longer being exposed to an effective amount of theanti-addiction treatment.

In another related embodiment, the present invention provides a methodof treating relapse use of an addictive agent or practice of anaddictive or compulsive behaviour, comprising providing an effectiveamount of a peroxisome proliferator-activated receptor gamma (PPARγagonist) to a subject who has undergone a period of abstinence from, orlimited or reduced use of, the addictive agent or practice of theaddictive or compulsive behaviour. In certain embodiments, the subjecthas undergone physiological withdrawal from the addictive agent duringthe period of abstinence from, or limited or reduced use of, theaddictive agent or due to no longer being exposed to an effective amountof the anti-addiction treatment.

In a further embodiment, the present invention includes a method oftreating relapse use of an addictive agent or practice of an addictiveor compulsive behaviour, comprising providing an effective amount of aperoxisome proliferator-activated receptor gamma (PPARγ agonist) to asubject who has undergone a period of abstinence from, or limited orreduced use of, the addictive agent or practice of the addictive orcompulsive behaviour, and also providing to the subject an additionaltherapeutic agent wherein each of the PPARγ agonist and the additionaltherapeutic agent contribute to the effective treatment of the relapseuse or practice. In certain embodiments, the subject has undergonephysiological withdrawal from the addictive agent during the period ofabstinence from, or limited or reduced use of, the addictive agent ordue to no longer being exposed to an effective amount of theanti-addiction treatment.

In another related embodiment, the present invention provides a methodof preventing relapse use of an addictive agent or practive of anaddictive or compulsive behaviour, comprising providing an effectiveamount of a peroxisone proliferator-activated receptor gamma (PPARγagonist) to a subject, wherein the subject previously reduced oreliminated use of the addictive agent or practice of the addictive orcompulsive behaviour in response to treatment with an effective amountof an anti-addiction treatment, and wherein the subject is no longerexposed to an effective amount of the anti-addiction treatment. Incertain embodiments, the subject is no longer exposed to an effectiveamount of an anti-addiction agent because the subject has becomeconditioned to the anti-addiction agent. In certain embodiments, thesubject is no longer exposed to an effective amount of theanti-addiction treatment because the subject has reduced or eliminatedexposure to the anti-addiction treatment.

In a related embodiment, the present invention provides a method ofpreventing relapse use of an addictive agent or practive of an addictiveor compulsive behaviour, comprising providing an effective amount of aperoxisone proliferator-activated receptor gamma (PPARγ agonist) to asubject, wherein the subject previously reduced or eliminated use of theaddictive agent or practice of the addictive or compulsive behaviour inresponse to treatment with an effective amount of an anti-addictiontreatment, and wherein the subject is no longer exposed to an effectiveamount of the anti-addiction treatment, and also providing to thesubject an additional therapeutic agent, wherein each of the PPARγagonist and the additional therapeutic agent contribute to the effectiveprevention of the relapse use or practice. In certain embodiments, thesubject is no longer exposed to an effective amount of an anti-addictionagent because the subject has become conditioned to the anti-addictionagent. In certain embodiments, the subject is no longer exposed to aneffective amount of the anti-addiction treatment because the subject hasreduced or eliminated exposure to the anti-addiction treatment.

In additional embodiments, the present invention includes a method oftreating relapse use of an addictive agent or practive of an addictiveor compulsive behaviour, comprising providing an effective amount of aperoxisone proliferator-activated receptor gamma (PPARγ agonist) to asubject, wherein the subject previously reduced or eliminated use of theaddictive agent or practice of the addictive or compulsive behaviour inresponse to treatment with an effective amount of an anti-addictiontreatment, and wherein the subject is no longer exposed to an effectiveamount of the anti-addiction treatment. In certain embodiments, thesubject is no longer exposed to an effective amount of an anti-addictionagent because the subject has become conditioned to the anti-addictionagent. In certain embodiments, the subject is no longer exposed to aneffective amount of the anti-addiction treatment because the subject hasreduced or eliminated exposure to the anti-addiction treatment.

In a further embodiment, the present invention includes a method oftreating relapse use of an addictive agent or practive of an addictiveor compulsive behaviour, comprising providing an effective amount of aperoxisone proliferator-activated receptor gamma (PPARγ agonist) to asubject, wherein the subject previously reduced or eliminated use of theaddictive agent or practice of the addictive or compulsive behaviour inresponse to treatment with an effective amount of an anti-addictiontreatment, and wherein the subject is no longer exposed to an effectiveamount of the anti-addiction treatment, and also providing to thesubject an additional therapeutic agent, wherein each of the PPARγagonist and the additional therapeutic agent contribute to the effectivetreatment of the relapse use or practice. In certain embodiments, thesubject is no longer exposed to an effective amount of an anti-addictionagent because the subject has become conditioned to the anti-addictionagent. In certain embodiments, the subject is no longer exposed to aneffective amount of the anti-addiction treatment because the subject hasreduced or eliminated exposure to the anti-addiction treatment.

In particular embodiments of any of the methods of treating orpreventing relapse use or practice of the present invention, the PPARγagonist is pioglitazone and the additional therapeutic agent isnaltrexone.

In particular embodiments of any of the methods of treating orpreventing relapse use or practice of the present invention, the relapseuse or relapse practice is stress-induced.

In another embodiment, the present invention provides a method ofreducing one or more symptoms associated with physiological withdrawalfrom an addictive agent, comprising providing an effective amount of aperoxisome proliferator-activated receptor gamma (PPARγ) agonist to asubject undergoing physiological withdrawal from an addictive agent.

In a related embodiment, the present invention provides a method ofreducing one or more symptoms associated with physiological withdrawalfrom an addictive agent, comprising providing an effective amount of aperoxisome proliferator-activated receptor gamma (PPARγ) agonist and anadditional therapeutic agent to a subject undergoing physiologicalwithdrawal from an addictive agent, wherein each of the PPARγ agonistand the additional therapeutic agent contribute to reducing one or moresymptoms associated with physical withdrawal from the addictive agent.

In particular embodiments of methods of reducing one or more symptomsassociated with physiological withdrawal from an addictive agentaccording to the present invention, the PPARγ agonist is athiazolidinedione (TZD). In certain embodiments, the TZD ispioglitazone, rosiglitazone, ciglitazone, troglitazone, englitazone,rivoglitazone or darglidazone. In certain embodiments, the additionaltherapeutic agent is an opioid antagonist, a mixed opioid partialagonist/antagonist, an antidepressant, an antiepileptic, an antiemetic,a corticotrophin-releasing factor-1 (CRF-1) receptor antagonist, aselective serotonin-3 (5-HT3) antagonist, a 5-HT_(2A/2C) antagonist, ora cannabinoid-1 (CB1) receptor antagonist.

In another embodiment, the present invention includes a pharmaceuticalcomposition, comprising a peroxisome proliferator-activated receptorgamma (PPARγ) agonist and an additional therapeutic agent, wherein eachof the PPARγ agonist and the additional therapeutic agent contribute tothe effective treatment or prevention of an addiction. In certainembodiments, the PPARγ agonist is a thiazolidinedione (TZD). In certainembodiments, the TZD is pioglitazone, rosiglitazone, ciglitazone,troglitazone, englitazone, rivoglitazone or darglidazone.

In one embodiment, the pharmaceutical composition is effective in thetreatment of an addiction to an addictive agent. In particularembodiments, the addictive agent is alcohol, nicotine, marijuana, amarijuana derivative, an opioid agonist, a benzodiazepine, abarbiturate, or a psychostimulant.

In another embodiment, the pharmaceutical composition is effective inthe treatment of an addiction to an addictive or compulsive behaviour.In particular embodiments, the addictive or compulsive behavior ispathological gambling, pathological overeating, pathological use ofelectronic devices, pathological use of electronic video games,pathological use of electronic communication devices, pathological useof cellular telephones, addiction to pornography, sex addiction,obsessive compulsive disorder, compulsive spending, anorexia, bulimia,intermittent explosive disorder, kleptomania, pyromania,trichotillomania, compulsive overexercising, and compulsive overworking.

In certain embodiments of pharmaceutical compositions of the presentinvention, the additional therapeutic agent is an opioid antagonist, amixed opioid partial agonist/antagonist, an antidepressant, anantiepileptic, an antiemetic, a corticotrophin-releasing factor-1(CRF-1) receptor antagonist, a selective serotonin-3 (5-HT3) antagonist,a 5-HT_(2A/2C) antagonist, and a cannabinoid-1 (CB1) receptorantagonist. In one embodiment, the opioid antagonist is naltrexone ornalmefene. In one embodiment, the antidepressant is fluoxetine,mirtazapine, or bupropion. In one embodiment, the antiepileptic isselected from the group consisting of: topiramate, levetiracetam, andgabapentin. In one embodiment, the CRF-1 receptor antagonist isantalarmin. In one embodiment, the selective serotonin-3 (5-HT3)antagonist is ondansetron. In one embodiment, the cannabinoid-1 (CB1)receptor antagonist is rimonabant or tanarabant. In one embodiment, themixed opioid agonist/antagonist is buprenorphine.

In a particular embodiment of a pharmaceutical composition of thepresent invention, the addictive agent is alcohol and the additionaltherapeutic agent is an opioid antagonist or a mixed opioidantagonist/partial agonist. In one embodiment, the opioid antagonist isnaltrexone. In one embodiment, the mixed opioid partialagonist/antagonist is buprenorphine.

In a particular embodiment of a pharmaceutical composition of thepresent invention, the addictive agent is nicotine and the additionaltherapeutic agent is an antidepressant. In one embodiment, theantidepressant is bupropion.

In a particular embodiment of a pharmaceutical composition of thepresent invention, the addictive agent is a psychostimulant and theadditional therapeutic agent is an antidepressant. In one embodiment,the antidepressant is bupropion.

In a particular embodiment of a pharmaceutical composition of thepresent invention, the addictive agent comprises two or more addictiveagents and the additional therapeutic agent is an opioid antagonist or amixed opioid partial agonist/antagonist. In one embodiment, the opioidantagonist is naltrexone or nalmefene. In one embodiment, the mixedopioid partial agonist/antagonist is buprenorphine.

In a particular embodiment of a pharmaceutical composition of thepresent invention, the PPARγ agonist is pioglitazone and the additionaltherapeutic agent is naltrexone.

In further related embodiments, the present invention includes unitdosage forms of a pharmaceutical composition adapted for the treatmentof an addiction, wherein said unit dosage form comprises a peroxisomeproliferator-activated receptor gamma (PPARγ) agonist and an additionaltherapeutic agent, wherein said unit dosage form comprises the PPARγagonist and the additional therapeutic agent in a combined amounteffective in the treatment of an addiction, and wherein each of thePPARγ agonist and the additional therapeutic agent contribute to theeffective treatment or prevention of the addiction. In particularembodiments, the PPARγ agonist is a thiazolidinedione (TZD). In certainembodiments, the TZD is pioglitazone, rosiglitazone, ciglitazone,troglitazone, englitazone, rivoglitazone or darglidazone. In certainembodiments, the additional therapeutic agent is an opioid antagonist, amixed opioid partial agonist/antagonist, an antidepressant, anantiepileptic, an antiemetic, a corticotrophin-releasing factor-1(CRF-1) receptor antagonist, a selective serotonin-3 (5-HT3) antagonist,a 5-HT_(2A/2C) antagonist, or a cannabinoid-1 (CB1) receptor antagonist.In one embodiment, the opioid antagonist is naltrexone or nalmefene. Inone embodiment, the antidepressant is fluoxetine, mirtazapine, orbupropion. In one embodiment, the antiepileptic is selected from thegroup consisting of: topiramate, levetiracetam, and gabapentin. In oneembodiment, the CRF-1 receptor antagonist is antalarmin. In oneembodiment, the selective serotonin-3 (5-HT3) antagonist is ondansetron.In one embodiment, the cannabinoid-1 (CB1) receptor antagonist isrimonabant or tanarabant. In one embodiment, the mixed opioidagonist/antagonist is buprenorphine.

In one particular embodiment of a unit dosage form of the presentinvention, the PPARγ agonist is pioglitazone and the additionaltherapeutic agent is naltrexone.

In another related embodiment, the present invention includes a kituseful for the treatment or prevention of an addiction, comprising: afirst container comprising a peroxisome proliferator-activated receptorgamma (PPARγ) agonist; and a second container comprising an additionaltherapeutic agent, wherein each of the PPARγ agonist and the additionaltherapeutic agent contribute to the effective treatment of prevention ofan addiction. In particular embodiments, the PPARγ agonist is athiazolidinedione (TZD). In certain embodiments, the TZD ispioglitazone, rosiglitazone, ciglitazone, troglitazone, englitazone,rivoglitazone or darglidazone. In certain embodiments, the additionaltherapeutic agent is an opioid antagonist, a mixed opioid partialagonist/antagonist, an antidepressant, an antiepileptic, an antiemetic,a corticotrophin-releasing factor-1 (CRF-1) receptor antagonist, aselective serotonin-3 (5-HT3) antagonist, a 5-HT_(2A/2C) antagonist, ora cannabinoid-1 (CB1) receptor antagonist. In one embodiment, the opioidantagonist is naltrexone or nalmefene. In one embodiment, theantidepressant is fluoxetine, mirtazapine, or bupropion. In oneembodiment, the antiepileptic is selected from the group consisting of:topiramate, levetiracetam, and gabapentin. In one embodiment, the CRF-1receptor antagonist is antalarmin. In one embodiment, the selectiveserotonin-3 (5-HT3) antagonist is ondansetron. In one embodiment, thecannabinoid-1 (CB1) receptor antagonist is rimonabant or tanarabant. Inone embodiment, the mixed opioid agonist/antagonist is buprenorphine.

In one particular embodiment of a kit of the present invention, thePPARγ agonist is pioglitazone and the additional therapeutic agent isnaltrexone.

In one particular embodiment of a kit of the present invention, theaddictive agent is alcohol and the additional therapeutic agent is anopioid antagonist or a mixed opioid antagonist/partial agonist. In oneembodiment, the opioid antagonist is naltrexone. In one embodiment, themixed opioid partial agonist/antagonist is buprenorphine.

In one particular embodiment of a kit of the present invention, theaddictive agent is nicotine and the additional therapeutic agent is anantidepressant. In one embodiment, the antidepressant is bupropion.

In one particular embodiment of a kit of the present invention, theaddictive agent is a psychostimulant and the additional therapeuticagent is an antidepressant. In one embodiment, the antidepressant isbupropion.

In one particular embodiment of a kit of the present invention, theaddictive agent comprises two or more addictive agents and theadditional therapeutic agent is an opioid antagonist or a mixed opioidpartial agonist/antagonist. In one embodiment, the opioid antagonist isnaltrexone or nalmefene. In one embodiment, the mixed opioid partialagonist/antagonist is buprenorphine.

In a further embodiment, the present invention includes a kit comprisingone or more unit dosage forms of a peroxisome proliferator-activatedreceptor gamma (PPARγ) agonist and one or more unit dosage forms ofnicotine. In one embodiment, the one or more unit dosage forms ofnicotine comprise two or more different amounts of nicotine. In oneembodiment, the PPARγ agonist is a thiazolidinedione (TZD). In oneembodiment, the TZD is pioglitazone, rosiglitazone, ciglitazone,troglitazone, englitazone, rivoglitazone or darglidazone.

In additional embodiment, the present invention includes a method ofpreventing a subject from becoming addicted, or reducing the likelihoodthat a subject will become addicted, to an addictive therapeutic agent,comprising providing to a subject in need thereof an addictivetherapeutic agent, and an effective amount of a peroxisomeproliferator-activated receptor gamma (PPARγ agonist), wherein theeffective amount of the PPARγ agonist is an amount effective inpreventing the subject from becoming addicted, or reducing thelikelihood that the subject will become addicted, to the addictivetherapeutic agent. In particular embodiment, this method furthercomprises providing to the subject an additional therapeutic agent,wherein each of the PPARγ agonist and the additional therapeutic agentcontribute to preventing the subject from becoming addicted, or reducingthe likelihood that the subject will become addicted, to the addictivetherapeutic agent. In one embodiment, the addictive therapeutic agent isan opioid agonist. In certain embodiments, the opioid agonist iscodeine, morphine, noscapapine, hydrocodone, hydromorphone, oxycodone,tramadol, fentanyl, sufentanil, alfentanil, propoxyphene, methadone,butorphanol, destropropoxyphene, diamorphine, levorphanol, meptazinol,nalbuphine, pentazocine, dezocine, meperidine, or buprenorphine. In oneembodiment, the PPARγ agonist is a TZD. In particular embodiments, theTZD is pioglitazone, rosiglitazone, ciglitazone, troglitazone,englitazone, rivoglitazone or darglidazone. In one embodiment, the PPARγagonist is pioglitazone, and the addictive therapeutic agent isoxycodone. In another embodiment, the the PPARγ agonist is pioglitazone,and the addictive therapeutic agent is hydrocodone. In a furtherembodiment, the PPARγ agonist is rosiglitazone, and the addictivetherapeutic agent is oxycodone. In a further embodiment, the PPARγagonist is rosiglitazone, and the addictive therapeutic agent ishydrocodone. In another embodiment, the PPARγ agonist is pioglitazone,and the addictive therapeutic agent is fentanyl. In a furtherembodiment, the PPARγ agonist is rosiglitazone, and the addictivetherapeutic agent is fentanyl.

In related embodiments, the present invention also includespharmaceutical compositions, and unit dosage forms thereof, comprisingan effective amount of an addictive therapeutic agent and an effectiveamount of a PPARγ agonist, wherein the effective amount of the PPARγagonist is an amount effective in preventing the subject from becomingaddicted, or reducing the likelihood that the subject will becomeaddicted, to the addictive therapeutic agent. In one embodiment, theaddictive therapeutic agent is an opioid agonist. In particularembodiments, the opioid agonist is alfentanil, allylprodine,alphaprodine, anileridine, apomorphine, benzylmorphine, beta-hydroxy3-methylfentanyl, bezitramide, buprenorphine, butorphanol, carfentanil,clonitazene, codeine, desomorphine, destropropoxyphene, dextromoramide,dezocine, diacetylmorphine (heroin), diamorphine, diampromide,dihydrocodeine, dihydroetorphine, dihydromorphine, dimenoxadol,dimepheptanol, dimethylthiambutene, dioxaphetylbutyrate, dipipanone,eptazocine, ethoheptazine, ethylmethylthiambutene, ethylmorphine,etonitazene, etorphine, fentanyl, hydrocodone, hydromorphone,hydroxypethidine, isomethadone, ketobemidone, LMM, levorphanol,levophenacylmorphan, lofentanil, meperidine, meptizinol, metapon,metazocine, methadone, methadyl acetate, metopon, morphine, myrophine,nalbuphine, narceine, nicomorphine, norlevorphanol, normethadone,normorphine, norpipanone, noscapine, opium, oxycodone, oxymorphone,papaverine, pentazocine, phenadoxone, phenomorphan, phenoperidine,piminodine, piritramide, propheptazine, promedol, properidine,propoxyphene, remifentanil, sufentanil, thebaine, tildine, or tramadol,or any combination thereof. In particular embodiments, the TZD ispioglitazone, rosiglitazone, ciglitazone, troglitazone, englitazone,rivoglitazone or darglidazone. In one embodiment, the PPARγ agonist ispioglitazone, and the addictive therapeutic agent is oxycodone. Inanother embodiment, the the PPARγ agonist is pioglitazone, and theaddictive therapeutic agent is hydrocodone. In a further embodiment, thePPARγ agonist is rosiglitazone, and the addictive therapeutic agent isoxycodone. In a further embodiment, the PPARγ agonist is rosiglitazone,and the addictive therapeutic agent is hydrocodone. In anotherembodiment, the PPARγ agonist is pioglitazone, and the addictivetherapeutic agent is fentanyl. In a further embodiment, the PPARγagonist is rosiglitazone, and the addictive therapeutic agent isfentanyl. In one embodiment, the combination of a PPARγ agonist, such aspioglitazone or rosiglitazone, and fentanyl may be deliveredtransdermally, e.g., using a patch comprising both agents.Alternatively, each agent may be delivered via a different route.

In certain embodiments of the methods of the present invention, thesubject is addicted to an addictive agent, or at risk for relapse use ofan addictive agent. In various embodiments, the pharmaceuticalcompositions, unit dosage forms, and kits of the present invention areuseful for the treatment or prevention of addiction to an addictiveagent or relapse use of an addictive agent. In particular embodiments,the addictive agent is alcohol, nicotine, marijuana, a marijuanaderivative, an opioid agonist, a benzodiazepine, a barbiturate, or apsychostimulant. In certain embodiments, the opioid agonist is selectedfrom the group consisting of: morphine, methadone, fentanyl, sufentaniland heroin. In certain embodiments, the psychostimulant is cocaine,amphetamine or an amphetamine derivative. In addition, the subject maybe addicted to more than one addictive agent, and the pharmaceuticalcompositions, unit dosage forms, and kits may be useful for treating orpreventing addiction or relapse use of more than one addictive agent.

In other embodiments of the present invention, the subject is addictedto an addictive or compulsive behavior or at risk for relapse practiceof an addictive or compulsive behaviour. In various embodiments, thepharmaceutical compositions, unit dosage forms, and kits of the presentinvention are useful for the treatment or prevention of addiction to anaddictive or compulsive behaviour or relapse use of an addictive orcompulsive behaviour. In particular embodiments, the addictive orcompulsive behavior is pathological gambling, pathological overeating,pathological use of electronic devices, pathological use of electronicvideo games, pathological use of electronic communication devices,pathological use of cellular telephones, addiction to pornography, sexaddiction, obsessive compulsive disorder, compulsive spending, anorexia,bulimia, intermittent explosive disorder, kleptomania, pyromania,trichotillomania, compulsive overexercising, and compulsive overworking.In addition, the subject may be addicted to more than one addictive orcompulsive behaviour, and the pharmaceutical compositions, unit dosageforms, and kits may be useful for treating or preventing addiction orrelapse use of more than one addictive or compulsive behaviour.

In a further related embodiment, the present invention includes a kitcomprising one or more unit dosage forms of a peroxisomeproliferator-activated receptor gamma (PPARγ agonist) and one or moreunit dosage forms of nicotine. In one embodiment, the PPARγ agonist is athiazolidinedione (TZD). In certain embodiments, the TZD is selectedfrom the group consisting of pioglitazone, rosiglitazone, ciglitazone,troglitazone, englitazone, rivoglitazone and darglidazone.

In another related embodiment, the present invention includes a deliverysystem comprising an amount of nicotine and an amount of a peroxisomeproliferator-activated receptor gamma (PPARγ agonist) effective for thetreatment of nicotine addition. In various embodiments, the amount ofnicotine and the amount of the PPARγ agonist are present in atransdermal patch, an oral lozenge, or a chewing gum.

In a further related embodiment, the present invention includes a methodof preventing a subject from becoming addicted, or reducing thelikelihood that a subject will become addicted, to an addictivetherapeutic agent, comprising providing to a subject in need thereof anaddictive therapeutic agent and an effective amount of athiazolidinedione (TZD), wherein the effective amount of the TZD is anamount effective in preventing the subject from becoming addicted, orreducing the likelihood that the subject will become addicted, to theaddictive therapeutic agent.

In a related embodiment, the present invention provides a unit dosageform of a pharmaceutical composition, wherein said unit dosage formcomprises an effective amount of an addictive therapeutic agent and aneffective amount of a thiazolidinedione (TZD), wherein the effectiveamount of the TZD is an amount effective in preventing the subject frombecoming addicted, or reducing the likelihood that the subject willbecome addicted, to the addictive therapeutic agent. In particularembodiments, the addictive therapeutic agent is an opioid agonist.

In a further related embodiment, the present invention includes adelivery system comprising an amount of nicotine and an amount of athiazolidinedione (TZD) effective for the treatment of nicotineaddition.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a graph depicting the effect of acute administration of 10.0or 30.0 mg/kg of pioglitazone (Pio 10 and Pio 30, respectively) onalcohol intake in Marchigian Sardinian alcohol-preferring (msP) rats.Controls were treated with vehicle only (Veh). Values represent themean±sem of alcohol intake. Significant difference from controls isindicated: *p<0.05.

FIG. 2 is a graph depicting the effect of acute administration of 0.25mg/kg of naltrexone (Ntx) alone or in combination with 10.0 or 30.0mg/kg of pioglitazone (Pio 10 and Pio 30, respectively) on alcoholintake in msP rats. Controls were treated with drugs' vehicles(Veh+Veh). Values represent the mean±sem of alcohol intake. Significantdifference from controls is indicated: **p<0.01 and *p<0.05.

FIGS. 3A-3D are graphs demonstrating the effect of subchronicadministration of 10.0 or 30.0 mg/kg of pioglitazone (Pio 10 and Pio 30,respectively) on alcohol intake in msP rats. Controls were treated withdrug vehicle (Veh). The values shown in FIGS. 3A-3C represent themean±sem of daily alcohol intake measured at: 2 hours (FIG. 3A); 8 hours(FIG. 3B); and 24 hours (FIG. 3C) from the beginning of the dark phaseof the daily light/dark cycle. FIG. 3D shows daily food intake measuredat 24 hour intervals. Significant difference from controls is indicated:*p<0.05.

FIGS. 4A-4D are graphs demonstrating the effect of subchronicadministration of 0.25 mg/kg of naltrexone (Ntx) alone or in combinationwith 10.0 or 30.0 mg/kg of pioglitazone (Pio 10 and Pio 30,respectively) on alcohol intake in msP rats. Controls were treated withdrug vehicle (Veh+Veh). The values shown in FIGS. 4A-4C represent themean±sem of daily alcohol intake measured at: 2 hours (FIG. 4A); 8 hours(FIG. 4B); and 24 hours (FIG. 4C) from the beginning of the dark phaseof the daily light/dark cycle. FIG. 4D shows daily food intake measuredat 24 hour intervals. Significant difference from controls is indicated:*p<0.05.

FIG. 5 is a bar graph depicting the effect of pioglitazone onyohimbine-induced reinstatement of ethanol seeking behaviour. Comparedto extinction (Ext), yohimbine elicited a significant reinstatement ofresponding that was markedly reduced by pre-treatment with 10.0 and 30.0mg/kg of pioglitazone (Pio 10 and 30, respectively). Values representthe mean (±SEM) number of responses at the active lever. Significantdifference from controls (pioglitazone vehicle; Veh) is indicated:**P<0.05.

FIG. 6 is a bar graph depicting the lack of effect of pioglitazone oncue-induced reinstatement of ethanol seeking behaviour. Values shownrepresent the mean (±SEM) number of responses at the active or inactivelevers. Conditioning: responses of the last 10% alcohol (filled circle)and water (open circle) session of the discrimination phase. Extinction(EXT): responses during the last day of this phase. Reinstatement:responses in rats exposed to stimuli predictive of alcohol (S⁺/CS⁺) orwater (S⁻/CS⁻) availability. Significant difference from Ext isindicated: **P<0.01.

FIG. 7 is a graph depicting the effect of treatment with ciglitazone 5.0(Cig 5) or 20.0 mg/kg (Cig 20) or its vehicle (Veh) on FR1 ethanolself-administration in Wistar rats. Each lever response resulted in thedelivery of 0.1 ml of 10% ethanol. Significant difference from controls(Veh) is indicated: *P<0.05.

FIG. 8 is a graph the effect of administration of 7.5 or 15.0 mg/kg ofrosiglitazone (Ros) on alcohol intake in msP rats. Controls were treatedwith the drug vehicle (Veh). Values represent the mean±sem of alcoholintake (g/kg) at the indicated time points. Significant difference fromcontrols is indicated: **<0.01 and *p<0.05.

FIGS. 9A and 9B are graphs depicting the effect of pre-treatment withthe PPARγ antagonist GW9662 on pioglitazone induced reduction of ethanoldrinking. FIG. 9A represents the effect of GW9662 (GW) given alone (1.0and 5.0 mg/kg) on ethanol intake in msP rats. FIG. 9B describes theeffect of pre-treatment with GW9662 on animals injected with 30 mg/kgpioglitazone (Pio) or its vehicle. The control group received vehiclesof both drugs (Veh+Veh). Values represent the mean±sem of alcohol intake(g/kg). Significant difference from controls is indicated: **p<0.01.

FIG. 10 is a graph depicting the effect of pre-treatment with the PPARγantagonist GW9662 given ICV on pioglitazone-induced reduction of ethanoldrinking. MsP rats received 5.0 μg/rat of GW9662 (GW) alone, 30 mg/kg ofpioglitazone (Pio) alone or their combination. Control group receivedvehicles of both drugs (Veh+Veh). Values represent the mean±sem ofalcohol intake (g/kg). Significant difference from controls isindicated: *p<0.05 and **p<0.01.

FIG. 11 is a graph depicting the effect of naltrexone (Ntx) onyohimbine-induced reinstatement of alcohol seeking. Compared toextinction (Ext) yohimbine elicited a significant reinstatement ofresponding that was not modified by pre-treatment with 0.25 and 1.0mg/kg of naltrexone. Values represent the mean (±SEM) number ofresponses at the active lever. Difference from controls (0.0) was notsignificant.

FIG. 12 is a graph depicting the effect of naltrexone (Ntx) oncue-induced reinstatement of alcohol seeking. Values represent the mean(±SEM) number of responses at the active lever. Conditioning: responsesof the last 10% alcohol (filled circle) and water (open circle) sessionof the discrimination phase. Extinction (Ext): responses during the lastday of this phase. Reinstatement: responses in rats exposed to stimulipredictive of alcohol (S⁺/CS⁺) or water (S⁻/CS⁻) availability. Treatmentwith 0.25 and 1.0 mg/kg of naltrexone significantly reduced cue-inducedreinstatement of alcohol-seeking; **p<0.01.

FIGS. 13A and 13B are graphs depicting the effect of naltrexone (ntx)plus pioglitazone (Pio) combination on: yohimbine-induced reinstatementof alcohol seeking (FIG. 13A) or cue-induced reinstatement of alcoholseeking (FIG. 13B). Compared to extinction (Ext), yohimbine elicited asignificant reinstatement of responding. The combination of Naltrexone(1.0 mg/kg) plus pioglitazone (10 and 30 mg/kg) significantly inhibitedyohimbine-induced reinstatement of alcohol seeking (FIG. 13A). Treatmentwith 1.0 mg/kg of naltrexone in combination with Pioglitazone (10.0 and30.0 mg/kg) also significantly reduced cue-induced reinstatement ofalcohol-seeking. Conditioning: responses of the last 10% alcohol (filledcircle) and water (open circle) session of the discrimination phase.Extinction (Ext): responses during the last day of this phase.Reinstatement: responses in rats exposed to stimuli predictive ofalcohol (S⁺/CS⁺) or water (S⁻/CS⁻) availability. Values represent themean (±SEM) number of responses at the active lever. Significantdifference from Ext is indicated: *P<0.05, **p<0.01.

FIG. 14 is a graph depicting the effect of administration of 10 mg/kg ofpioglitazone (Pio) alone or 3 mg/kg of fluoxetine alone or theircombination on alcohol intake in msP rats. Controls were treated withthe drug vehicles (Veh+Veh). Values represent the mean±sem of alcoholintake (g/kg). Significant difference from controls is indicated:*p<0.05 and **p<0.01.

FIG. 15 is a graph depicting the effect of administration of 10 mg/kg ofpioglitazone (Pio) alone or 5 mg/kg of mirtazapine alone or theircombination on alcohol intake in msP rats. Controls were treated withthe drug vehicles (Veh+Veh). Values represent the mean±sem of alcoholintake (g/kg). Significant difference from controls is indicated:*p<0.05.

FIG. 16 is a graph depicting the effect of administration of 10 mg/kg ofpioglitazone (Pio) alone or 30 mg/kg of topiramate alone or theircombination on alcohol intake in msP rats. Controls were treated withthe drug vehicles (Veh+Veh). Values represent the mean±sem of alcoholintake (g/kg). Significant difference from controls is indicated:*p<0.05.

FIG. 17 is a graph depicting the effect of administration of 10 mg/kg ofpioglitazone (Pio) alone or 100 mg/kg of levetiracetam (Leve) alone ortheir combination on alcohol intake in msP rats. Controls were treatedwith vehicles alone (Veh+Veh). Values represent the mean±sem of alcoholintake (g/kg). Significant difference from controls is indicated:*p<0.05 and **p<0.01.

FIG. 18 is a graph depicting the effect of administration of 10 mg/kg ofpioglitazone (Pio) alone or 30 mg/kg of gabapentin alone or theircombination on alcohol intake in msP rats. Controls were treated withvehicles (Veh+Veh). Values represent the mean±sem of alcohol intake(g/kg). Significant difference from controls is indicated: **p<0.01 and*p<0.05.

FIG. 19 is a graph depicting the effect of administration of 10 mg/kg ofpioglitazone (Pio) alone or 1.0 mg/kg of ondansetron alone or theircombination on alcohol intake in msP rats. Controls were treated withthe drug vehicles (Veh+Veh). Values represent the mean±sem of alcoholintake (g/kg). Significant difference from controls is indicated:**p<0.01 and *p<0.05.

FIG. 20 is a graph depicting the effect of administration of 10 mg/kg ofpioglitazone (Pio) alone or 15 mg/kg of antalarmin alone or theircombination on alcohol intake in msP rats. Controls were treated withvehicles (Veh+Veh). Values represent the mean±sem of alcohol intake(g/kg). Significant difference from controls is indicated: *p<0.05 and**p<0.01.

FIG. 21 is a graph depicting the effect of administration of 10 and 30mg/kg of pioglitazone (Pio) on an alcohol withdrawal score in Wistarrats. Controls received oral administration of alcohol vehicle. Valuesrepresent the mean±sem of total withdrawal score. Significant differencefrom controls is indicated: **p<0.01.

FIGS. 22A and 22B are graphs depicting the effect of treatment with 10.0or 30.0 mg/kg pioglitazone (10 or 30, respectively) or its vehicle (veh)on FR5 cocaine self-administration in Wistar rats. FIG. 22A shows thenumber of rewards at the active lever, with each five lever responseresulting in the delivery of one reward (0.25 mg/0.1 ml of cocaine).FIG. 22B shows the number of responses at the left inactive lever.Significant difference from controls (Veh) is indicated: **p<0.01.

FIGS. 23A and 23B are graphs depicting the effect of treatment withpioglitazone (30.0 mg/kg) or its vehicle (veh) on FR5 nicotineself-administration in Wistar rats. FIG. 23A shows the number of rewardsat the active lever, with each five lever response resulting in thedelivery of 0.25 mg/0.03 ml of nicotine. FIG. 23B shows the number ofresponses at the left inactive lever. Significant difference fromcontrols (Veh) is indicated: *p<0.05.

FIGS. 24A and 24B are graphs showing the effect of 5 mg/kg (Pio 5), 10mg/kg (Pio 10) or 30 mg/kg of (Pio 30) of pioglitazone onyohimbine-induced reinstatement of nicotine. Black filled circlesindicate the number of lever presses of the last nicotineself-administration day. Extinction (Ext) value represents the meanvalue of the last 3 extinction days. Compared to extinction, yohimbineelicited a significant reinstatement of responding that was prevented bytreatment with all pioglitazone doses. Values represent the mean (±SEM)number of responses at the active lever (FIG. 24A) or inactive lever(FIG. 24B). Significant difference from controls (Veh) is indicated:**p<0.01.

FIGS. 25A, 25B, and 25C are graphs showing the effect of treatment withpioglitazone (Pio), varenicline (Var) and bupropione (Bup) on: anxiety(FIG. 25A); depression (FIG. 25B); and craving (FIG. 25C), as measuredby Spielberger State-Trait Anxiety Inventory (STAI), Montgomery AsbergDepression Rating Scale (M.A.D.R.S 10 Item, and Visual Analogic Scale ofCraving.

FIG. 26 shows the effect of morphine, pioglitazone or their combinationon the tail-flick test (upper panel) or the tail-immersion test (lowerpanel). Mice were divided into 6 groups. Group 1 (n=8) received drugvehicles (v/v). Group 2 (n=9) received pioglitazone vehicle plus 30mg/kg morphine. Group 3 (n=8) and Group 4 (n=8) received 10 (pio 10) or30 mg/kg (pio 30) of pioglitazone followed by morphine vehicle. Group 5(n=8) and Group 6 (n=7) received 10 (pio 10/morphine) or 30 mg/kg (pio10/morf) of pioglitazone followed by morphine administration. Animalswere treated twice daily (between 9:00 and 10:00 a.m. and 9:00 and 10:00p.m.). Statistical difference from controls (v/v): **P<0.01 and *P<0.05.

FIG. 27 shows the effect of pioglitazone (Pio30) or its vehicle (0.0) onacquisition of heroin self-administration. Rats were divided into twogroups. Group 1 (n=10) received drug vehicles (0.0 mg/kg/ml) andself-administered heroin. Group 2 (n=10) received pioglitazone (30mg/kg/ml) and self-administered heroin. Animals were treated twicedaily. The upper panel shows the mean number of reinforced active leverresponses. The lower panel depicts the total daily dose of heroineself-administered by rats. Statistical difference from controls (0.0mg/kg/ml): **P<0.01 and *P<0.05.

FIG. 28 shows the effect of 10 mg (Pio10) and 30 mg (Pio30) ofpioglitazone or its vehicle (0.0) on acquisition of foodself-administration. Rats were divided into three groups. Animals(n=8/group) were treated twice a day. Statistical difference fromcontrols (0.0 mg/kg/ml) was never significant.

FIG. 29 shows the effect of 10 mg (Pio10) and 30 mg (Pio30) ofpioglitazone or its vehicle (0.0) on food self-administration. Rats weredivided into three groups (n=8/group). Rats were treated twice a day.Statistical difference from controls (0.0 mg/kg/ml) was neversignificant.

FIG. 30 shows the effect of treatment with pioglitazone (Pio) andnaltrexone (Ntx) on anxiety (FIG. 30A); depression (FIG. 30B); andobsession/compulsion for alcohol (FIG. 30C) in alcoholic patients.Controls (Ctr) did not receive drug treatment. Abbreviations:Spielberger State-Trait Anxiety Inventory (STAI); Montgomery AsbergDepression Rating Scale (M.A.D.R.S 10 Item); and Obsessive CompulsiveDrinking Scale (OCDS).

DETAILED DESCRIPTION

The present invention is based, in large part, upon the findingdescribed herein that peroxisome proliferator-activated receptor gamma(PPARγ) agonists are useful in the treatment and prevention ofaddictions and relapse use of an addictive agent or behaviour.Accordingly, the present invention provides methods and relatedcompositions, formulations, unit dosage forms and kits for the treatmentand prevention of addiction and relapse use, which include one or morePPARγ agonists, alone or in combination with one or more additionaltherapeutic agents in which each of the PPARγ agonist and the additionaltherapeutic agent(s) contribute to the effective treatment or preventionof the addiction.

As demonstrated in the accompanying Examples, a variety of differentthiazolidinediones (TZDs) were shown to reduce intake of an addictiveagent in various models of addiction. For example, each of the TZDs,pioglitazone, ciglitazone, and rosiglitazone, significantly reducedethanol consumption in rat models of alcohol addiction (Examples 1, 3,7, and 8). The effect was evident for both acute and subchronicadministration of a TZD (Examples 1 and 2). In addition, TZDs were shownto reduce cocaine use in a rat model of cocaine addiction (Example 23)and a rat model of nicotine addiction (Example 24). This effect of thePPARγ agonists was shown to be mediated by the activation of PPARγreceptors using two different PPARγ agonists (Examples 9 and 10). Inaddition, an observational study of human patients using pioglitazonefor the treatment of diabetes confirmed that this PPARγ agonist wasefficacious in reducing ethanol abuse (Example 22). These data establishthat PPARγ agonists may be used to treat and prevent addiction to avariety of different addictive agents.

In addition, the accompanying Examples demonstrate that PPARγ agonistsused in combination with a variety of different therapeutic agentssubstantially reduced intake of an addictive agent. For example, it isshown that acute or subchronic treatment with the TZD, pioglitazone,enhanced the inhibitor action of the opioid antagonist, naltrexone, onethanol intake (Examples 2 and 4). These data demonstrate that the useof a PPARγ agonist in combination with an opioid antagonist would haveincreased, e.g., additive or synergistic, efficacy in treating orpreventing addiction.

In addition to reducing use of an addictive agent, PPARγ agonists werealso able to reduce or prevent relapse use, or reinstatement, ofaddictive agents. As described in Example 5, treatment with pioglitazonesignificantly reduced stress-induced reinstatement of alcohol use.Interestingly, however, it did not significantly reduce cue-inducedreinstatement of alcohol use (Example 6). In contrast, the opioidantagonist, naltrexone, reduced cue-induced reinstatement of alcoholuse, but not stress-induced reinstatement of alcohol use (Examples 12and 11). The data support the concept that the combination of a PPARγagonist and an opioid antagonist would have an enhanced ability toprevent relapse use of an addictive agent, since such a combinationwould prevent both stress-induced and cue-induced relapse use. In fact,treatment with the combination of the PPARγ agonist, pioglitazone, andthe opioid antagonist, naltrexone, resulted in a significantly reducedreinstatement of both stress-induced and cue-induced alcohol use(Example 13).

PPARγ agonists also worked synergistically with other classes oftherapeutic agents in reducing or preventing addiction and relapse use.For example, the TZD, pioglitazone, used in combination with a varietyof different classes of antidepressants, including fluoxetine andmirtazapine, worked synergistically in reducing ethanol consumption inan animal model of ethanol addiction (Examples 14 and 15).Anti-epileptics, including topiramate, levetiracetam, and gabapentin,showed synergism in combination with a TZD in reducing ethanol intake(Examples 16-18), and antiemetics, including the serotonin-3 (5-HT3)receptor selective antagonist, ondansetron, and the corticotrophinreleasing factor 1 receptor selective antagonist, antalarmin, alsoshowed synergism in combination with a TZD in reducing alcoholconsumption (Examples 19 and 20).

Interestingly, the experiments described in the accompanying Examplesalso showed that PPARγ agonists significantly reduced withdrawalsymptoms in alcohol-addicted animals (Example 21).

In summary, the present invention demonstrates that treatment with PPARγagonists represent a novel pharmacological approach for the treatmentand prevention of addiction, since it reduces addictive agentconsumption and recidivism associated to stress exposure.

In addition, considering that the physiopathology of addiction hasfeatures (i.e., drug craving, compulsive behaviour triggered by drugdesire, withdrawal, relapse behaviour, neurological damages, cognitiveimpairment) common to all drugs of abuse it is reasonable to think thatPPARγ agonists will be useful also for the treatment of dependence toother addictive agents or behaviours, including, e.g., opiates(morphine, heroin methadone), psychostimulants (cocaine,methamphetamine, and amphetamine related compounds in general),nicotine, gamma hydroxybutyrate (GHB), phencyclidine, and phencyclidinederivatives, etc.

PPARγ agonists showed efficacy also in combination with opioidantagonists; co-administration of the two drugs resulted in additivitywith regard to the effect on ethanol drinking and expanded the efficacyof the opioid antagonist on stress induced reinstatement. In aco-administration regimen, it is of particular significance to note theneuroprotective anticonvulsant and withdrawal-reducing effect of TDZs,especially during the early treatment phase. In fact, opioid antagonistsdo not result in any amelioration of withdrawal symptoms and this, ingeneral, may contribute to the early treatment drop out and lowcompliance often reported with these drugs.

The ability of TDZs to normalize hepatic function may also have positiveconsequences in exploitation of a combined treatment approach. In fact,the clinical condition of alcoholic patients is, in general,compromised, especially during the early detoxification phase. Thus,rapid recovery and amelioration from a pathological state could improvetreatment retention.

A. Methods of Treating and Preventing Addictions Using PPARγ Agonist(s)

Thus, the present invention includes methods of treating or preventingan addiction, comprising providing one or more PPARγ agonists to asubject having an addiction or at risk for developing an addiction. Invarious embodiments, the subject is addicted to an addictive agent orbehaviour, including, but not limited to, any of the addictive agentsand behaviours described herein. The subject may be physically orphysiologically dependent on the substance or behaviour; the subject maybe psychologically dependent; or the subject may be both physically andpsychologically dependent. The subject may be addicted to one or morethan one addictive agent or behaviour.

As used herein, unless the context makes clear otherwise, “treat,” andsimilar word such as “treatment,” “treating” etc., is an approach forobtaining beneficial or desired results, including and preferablyclinical results. Treatment can involve optionally either the reducingor amelioration of a disease or condition, (e.g., addiction, relapseuse, withdrawal), or the delaying of the progression of the disease orcondition (e.g., addiction relapse use, withdrawal).

As used herein, unless the context makes clear otherwise, “prevent,” andsimilar word such as “prevention,” “preventing” etc., is an approach forpreventing the onset or recurrence of a disease or condition, (e.g.,addiction, relapse use, withdrawal) or preventing the occurrence orrecurrence of the symptoms of a disease or condition, or optionally anapproach for delaying the onset or recurrence of a disease or conditionor delaying the occurrence or recurrence of the symptoms of a disease orcondition. Preventing also includes inhibiting the onset or recurrenceof a disease or condition, or one or more symptoms thereof, and reducingthe likelihood of onset or recurrence of a disease or condition, or oneor more symptoms thereof.

Generally, a subject is provided with an effective amount of a PPARγagonist. As used herein, an “effective amount” or a “therapeuticallyeffective amount” of a substance, e.g., a PPARγ agonist, is that amountsufficient to affect a desired biological or psychological effect, suchas beneficial results, including clinical results. For example, in thecontext of treating addiction using the methods of the presentinvention, an effective amount of a PPARγ agonist is that amountsufficient to cause the subject to reduce or discontinue use of anaddictive agent.

According to certain embodiments of the present invention, a subject isprovided with a PPARγ agonist alone, while in other embodiments, asubject is provided with a PPARγ agonist in combination with anadditional therapeutic agent. It is understood that the effective amountof either or both of a PPARγ agonist and an additional therapeutic agentmay be different when either is provided alone than when provided incombination. For example, when the PPARγ agonist and the additionaltherapeutic agent act synergistically, then a lower amount of the PPARγagonist, a lower amount of the additional therapeutic agent, or loweramounts of both the PPARγ agonist or the additional therapeutic agentmay be required to achieve the same therapeutic effect that would beprovided by either the PPARγ agonist or the additional therapeutic agentalone. In other embodiments, the same amount of the PPARγ agonist andthe additional therapeutic agent are used to provide an enhancedtherapeutic effect relative to the therapeutic effect provided by eitherthe PPARγ agonist or the additional therapeutic agent alone. As anotherexample, data in the Examples below indicate that patients addicted toalcohol and treated with the PPARγ agonist pioglitazone exhibitdecreased depression, and treatment of addicted patients with acombination of a PPARγ agonist and an antidepressant agent in accordancewith the present invention may provide an enhanced antidepressivetherapeutic effect as part of the treatment of the addictive disorder.

The subject may be any animal, including a mammal, and, particularly, ahuman.

In one aspect of the invention, the subject is first determined ordiagnosed to have an addiction, or to be at risk of developing anaddiction, by diagnostic testing, observation or analysis by a medicalcare provider. An effective amount of a PPARγ agonist, or an effectiveamount of a PPARγ agonist and one additional therapeutic agent, are thenprovided to the subject for treatment or prevention of the addiction. Inanother aspect of the invention, the subject is first determined ordiagnosed to have an addiction, or to be at risk of developing anaddiction, by diagnostic testing, observation or analysis by a medicalcare provider, but the subject has not been diagnosed or determined tohave diabetes or other insulin disorder. An effective amount of a PPARγagonist, or an effective amount of a PPARγ agonist and one additionaltherapeutic agent, are then provided to the subject for treatment orprevention of the addiction. The dosage of the PPARγ agonist, or thePPARγ agonist and the one additional therapeutic agent, may bespecifically determined by the medical practitioner for treatment orprevention of the addiction rather than for any other disorder ordisease.

In particular aspects, the subject is provided with a PPARγ agonist,alone or in combination with an additional therapeutic agent for theprimary purpose of treating or preventing an addiction. In relatedaspects of the methods of the present invention, the subject has notpreviously been provided with a PPARγ agonist for the treatment orprevention of any disease or disorder other than an addiction. Inparticular, in certain embodiments, the subject has not previously beenprovided with a PPARγ agonist for the treatment of insulin resistance ordiabetes. In a further related embodiment, the subject has not beendiagnosed with insulin resistance or diabetes.

In various embodiments of the present invention, the subject may beprovided with any PPARγ agonist, including any of the specific PPARγagonists described below. In particular embodiments, the PPARγ agonistis a TZD, including any of the TZDs described below. In certainembodiments, the TZD is pioglitazone, ciglitazone, rosiglitazone ortroglitazone.

In particular embodiments, the subject is suffering from or at risk foraddiction to any physically addictive agent or addictive or compulsivebehaviour, including, e.g., any of those described below. In particularembodiments, the subject is addicted to alcohol, cocaine, nicotine,marijuana, an opiate or other opioid agonist or methamphetamine or otherpsychostimulant, or phencyclidine and phencyclidine derivatives.

In particular embodiments, a subject is considered at risk of addictionor relapse to use of an addictive agent or practice of an addictivebehaviour when the subject has previously been addicted to the same or adifferent addictive agent or addictive or compulsive behaviour. Incertain embodiment, the subject is considered at risk of addiction orrelapse to use of an addictive agent or practice of an addictivebehaviour when the subject is psychologically addicted to an addictiveagent or addictive or compulsive behaviour, even if the subject is nolonger physically addicted.

In certain embodiments, the subject is addicted to or at risk ofbecoming addicted to a therapeutic agent provided to the patient totreat a disease or disorder, e.g., a pain medication. In a relatedembodiment, the subject may be at risk of abusing an addictivetherapeutic agent, such as a pain medication. Abusing an addictivetherapeutic agent, in certain embodiment, is understood to indicateusing the agent for a reason different than or in addition to itsprescribed use. In such a situation, a subject may be provided with bothan addictive therapeutic agent and a PPARγ agonist, alone or incombination with an additional therapeutic agent. For example, a subjectsuffering from pain, or at risk of pain, may be provided with an opioidagonist and a PPARγ agonist or TZD, e.g., pioglitazone, to both provideanalgesia and prevent or treat addiction to the opioid agonist. BecausePPARγ agonists have been shown to reduce neuropatic pain andinflammatory responses (see, e.g., Oliveira A. et al., Antinociceptiveand antiedematogenic activities of fenofibrate, an agonist of PPARalpha, and pioglitazone, an agonist of PPAR gamma, Eur J Pharmacol.561(1-3):194-201 (2007)), the PPARγ agonist may add to or enhance theanalgesic affect of the opioid agonist.

In particular embodiments in which a subject is provided with both aPPARγ agonist and an opioid agonist, the PPARγ agonist is a TZD. Incertain embodiments in which a subject is provided with both a PPARγagonist and an opioid agonist, the PPARγ agonist is pioglitazone,rosiglitazone, ciglitazone, troglitazone, englitazone, rivoglitazone, ordarglidazone. In particular embodiments in which a subject is providedwith both a PPARγ agonist and an opioid agonist (or opioid), the opioidagonist is a phenanthrene, a phenylheptylamine, or a phenylpiperidine.In certain embodiments in which a subject is provided with both a PPARγagonist and an opioid agonist, the opioid agonist is alfentanil,allylprodine, alphaprodine, anileridine, apomorphine, benzylmorphine,beta-hydroxy 3-methylfentanyl, bezitramide, carfentanil, clonitazene,codeine, desomorphine, dextromoramide, diacetylmorphine (heroin),diampromide, dihydrocodeine, dihydroetorphine, dihydromorphine,dimenoxadol, dimepheptanol, dimethylthiambutene, dioxaphetylbutyrate,dipipanone, eptazocine, ethoheptazine, ethylmethylthiambutene,ethylmorphine, etonitazene, etorphine, fentanyl, hydrocodone,hydromorphone, hydroxypethidine, isomethadone, ketobemidone, LMM,levorphanol, levophenacylmorphan, lofentanil, meperidine, metapon,metazocine, methadone, methadyl acetate, metopon, morphine, myrophine,narceine, nicomorphine, norlevorphanol, normethadone, normorphine,norpipanone, opium, oxycodone, oxymorphone, papaverine, phenadoxone,phenomorphan, phenoperidine, piminodine, piritramide, propheptazine,promedol, properidine, propoxyphene, remifentanil, sufentanil, thebaine,tildine, or tramadol, or any combination thereof.

Specific combinations of PPARγ agonists and opioid agonists contemplatedby the present invention include, but are not limited to pioglitazoneand codeine, pioglitazone and morphine, pioglitazone and noscapapine,pioglitazone and hydrocodone, pioglitazone and hydromorphone,pioglitazone and oxycodone, pioglitazone and tramadol, pioglitazone andfentanyl, pioglitazone and propoxyphene, pioglitazone and methadone,ciglitazone and codeine, ciglitazone and morphine, ciglitazone andnoscapapine, ciglitazone and hydrocodone, ciglitazone and hydromorphone,ciglitazone and oxycodone, ciglitazone and tramadol, ciglitazone andfentanyl, ciglitazone and propoxyphene, ciglitazone and methadone,rosiglitazone and codeine, rosiglitazone and morphine, rosiglitazone andnoscapapine, rosiglitazone and hydrocodone, rosiglitazone andhydromorphone, rosiglitazone and oxycodone, rosiglitazone and tramadol,rosiglitazone and fentanyl, rosiglitazone and propoxyphene,rosiglitazone and methadone, englitazone and codeine, englitazone andmorphine, englitazone and noscapapine, englitazone and hydrocodone,englitazone and hydromorphone, englitazone and oxycodone, englitazoneand tramadol, englitazone and fentanyl, englitazone and propoxyphene,englitazone and methadone, rivoglitazone and codeine, rivoglitazone andmorphine, rivoglitazone and noscapapine, rivoglitazone and hydrocodone,rivoglitazone and hydromorphone, rivoglitazone and oxycodone,rivoglitazone and tramadol, rivoglitazone and fentanyl, rivoglitazoneand propoxyphene, rivoglitazone and methadone, darglidazone and codeine,darglidazone and morphine, darglidazone and noscapapine, darglidazoneand hydrocodone, darglidazone and hydromorphone, darglidazone andoxycodone, darglidazone and tramadol, darglidazone and fentanyl,darglidazone and propoxyphene, or darglidazone and methadone. In oneparticular embodiment, the subject is contacted with both pioglitazoneand oxycodone. In another particular embodiment, the subject iscontacted with both pioglitazone and hydrocodone. Any of thesecombinations may be administered to a subject in combination, or presentin combination in a pharmaceutical composition, formulation, or kit ofthe present invention.

In various embodiments, the subject is provided with the PPARγ agonistat the same time that the subject is using an addictive agent, after thesubject has discontinued use of an addictive agent, or before thesubject begins using an addictive agent. In one particular embodiment,the subject is provided with the PPARγ agonist at the same time thesubject is provided with an opioid agonist. For example, a subject beingtreated with an opioid agonist (e.g., oxycodone) for pain may be given aPPARγ agonist (e.g., pioglitazone) at the same time, in order to reducethe likelihood that the subject will become addicted to the opioidagonist. In particular embodiments, the PPARγ agonist and opioid agonistmay be provided in a single co-formulation or composition. In oneembodiment, the co-formulation or composition comprises bothpioglitazone and oxycodone. In another embodiment, the co-formulation orcomposition comprises both pioglitazone and hydrocodone. In anotherparticular embodiment, the subject is provided with the PPARγ agonist atthe same time the subject is provided with nicotine or a nicotinecontaining substance. For example, a subject being treated with acontrolled dosage of nicotine for purposes of eliminating or reducingthe use of tobacco products may be given a PPARγ agonist (e.g.,pioglitazone) at the same time, in order to increase the likelihood thatthe subject will reduce or cease use of the tobacco product. Inparticular embodiments, the PPARγ agonist and nicotone may be providedin a single co-formulation or composition. In one embodiment, theco-formulation or composition comprises both pioglitazone and nicotine.

1. Addictive Agents

The term addiction is used to describe a recurring compulsion by anindividual to engage in some specific activity, despite harmfulconsequences to the individual's health, mental state or social life.The term is often reserved for drug addictions, but it is sometimesapplied to other compulsions, such as problem gambling, and compulsiveovereating. Factors that have been suggested as causes of addictioninclude genetic, biological/pharmacological and social factors.

The medical community now makes a careful theoretical distinctionbetween physical or physiological dependence (characterized by symptomsof withdrawal) and psychological dependence (sometimes referred tosimply as addiction). Addiction is now narrowly defined as“uncontrolled, compulsive use.” If there is no harm being suffered by,or damage done to, the patient or another party, then clinically it maybe considered compulsive, but to the definition of some it is notcategorized as “addiction”. In practice, the two kinds of addiction(physiological dependence and psychological dependence) are not alwayseasy to distinguish. Addictions often have both physical andpsychological components.

Physical dependence (or drug dependence) refers to a state resultingfrom habitual use of a drug, where negative physical withdrawal symptomsresult from abrupt discontinuation. Examples of addictive agents forwhich a user may develop a physical dependence include nicotine,opioids, barbiturates, benzodiazepines, alcohol, i.e., ethyl alcohol,GHB, and methaqualone.

Commonly abused stimulants such as cocaine or amphetamine class drugsare not believed to cause significant physical dependence. However,their potential for extreme physiological addiction can compel the userto consume amounts which become physically damaging, butlife-threatening withdrawal effects have not been observed.

As used herein, addictive agents includes any and all agents to which asubject can become addicted, either physically or psychologically, orboth. As noted above, addiction includes addiction to chemical entities,such as drugs, e.g., ethyl alcohol, nicotine, or cocaine, as well asaddiction to other behaviours, e.g., pathological gambling, pathologicalovereating, pathological use of electronic devices, e.g., BlackBerry®,pathological use of electronic video games, pathological use ofelectronic communication devices, pathological use of cellulartelephones, addiction to pornography, sex addiction, obsessivecompulsive disorder, compulsive spending, anorexia, bulimia,intermittent explosive disorder, kleptomania, pyromania,trichotillomania, compulsive overexercising, and compulsive overworking.

Addictive agents include addictive recreational drugs, as well asaddictive medications. Examples of addictive agents include, but are notlimited to, alcohol, e.g., ethyl alcohol, gamma hydroxybutyrate (GHB),caffeine, nicotine, cannabis (marijuana) and cannabis derivatives,opiates and other morphine-like opioid agonists such as heroin,phencyclidine and phencyclidine-like compounds, sedative ipnotics suchas benzodiazepines, methaqualone, mecloqualone, etaqualone andbarbiturates and psychostimulants such as cocaine, amphetamines andamphetamine-related drugs such as dextroamphetamine andmethylamphetamine. Other examples include LSD, psilocybin, ecstasy andother hallucinogens. Examples of addictive medications include, e.g.,benzodiazepines, barbiturates, and pain medications includingalfentanil, allylprodine, alphaprodine, anileridine benzylmorphine,bezitramide, buprenorphine, butorphanol, clonitazene, codeine,cyclazocine, desomorphine, dextromoramide, dezocine, diampromide,dihydrocodeine, dihydromorphine, dimenoxadol, dimepheptanol,dimethylthiambutene, dioxaphetyl butyrate, dipipanone, eptazocine,ethoheptazine, ethylmethylthiambutene, ethylmorphine, etonitazenefentanyl, heroin, hydrocodone, hydromorphone, hydroxypethidine,isomethadone, ketobemidone, levallorphan, levorphanol,levophenacylmorphan, lofentanil, meperidine, meptazinol, metazocine,methadone, metopon, morphine, myrophine, nalbuphine, narceine,nicomorphine, norlevorphanol, normethadone, nalorphine, normorphine,norpipanone, opium, oxycodone, OXYCONTIN®, oxymorphone, papaveretum,pentazocine, phenadoxone, phenomorphan, phenazocine, phenoperidine,piminodine, piritramide, propheptazine, promedol, properidine, propiram,propoxyphene sufentanil, tramadol, tilidine, salts thereof, mixtures ofany of the foregoing, mixed μ-agonists/antagonists, and the like.

In certain embodiments, a subject may be addicted to an opioid agonist.The terms “opioid agonist,” “opioid” and “opiate” are usedinterchangeably herein and are used to designate a group of drugs thatare, to varying degrees, opium- or morphine-like in their properties.Their main use is for pain relief. These agents work by binding toopioid receptors, which are found principally in the central nervoussystem and the gastrointestinal tract. Opiates are also addictiveagents. Opiates include, e.g., alfentanil, allylprodine, alphaprodine,anileridine, apomorphine, benzylmorphine, beta-hydroxy 3-methylfentanyl,bezitramide, carfentanil, clonitazene, codeine, desomorphine,dextromoramide, diacetylmorphine (heroin), diampromide, dihydrocodeine,dihydroetorphine, dihydromorphine, dimenoxadol, dimepheptanol,dimethylthiambutene, dioxaphetylbutyrate, dipipanone, eptazocine,ethoheptazine, ethylmethylthiambutene, ethylmorphine, etonitazene,etorphine, fentanyl, hydrocodone, hydromorphone, hydroxypethidine,isomethadone, ketobemidone, LMM, levorphanol, levophenacylmorphan,lofentanil, meperidine, metapon, metazocine, methadone, methadylacetate, metopon, morphine, myrophine, narceine, nicomorphine,norlevorphanol, normethadone, normorphine, norpipanone, opium,oxycodone, oxymorphone, papaverine, phenadoxone, phenomorphan,phenoperidine, piminodine, piritramide, propheptazine, promedol,properidine, propoxyphene, remifentanil, sufentanil, thebaine, tildine,and tramadol.

Naturally occurring opiates include, e.g., codeine, morphine, noscapine,papaverine, and thebaine. Semi-synthetic opioids include, e.g.,diacetylmorphine, hydrocodone, hydromorphone, levorphanol, metapon,nalorphine, naloxone, naltrexone, oxycodone, oxymorphone, and tramadol.Synthetic opioids include, e.g., ethoheptazine, fentanyl, levorphanol,meperidine, methadone, phenazocine, propoxyphene and sufentanil.

Three broad classifications of opiates are phenanthrenes,phenylheptylamines, and phenylpiperidines. Examples of phenanthrenesinclude codeine, etorpine, hydrocodone, hydromorphone, morphine,oxycodone, and oxymorphone. Examples of phenylheptylamines includedimepheptanol, dimenoxadol, dipipanone, isomethadone, methadone,methadyl acetate, and propoxyphene. Examples of phenylpiperidinesinclude alfentanyl, alphaprodine, beta-promedol, carfentanyl, fentanyl,lofentanil, meperidine, properidine, and sufentanil.

Specific psychostimulants include, by way of example, amphetamine,cocaine, dextroamphetamine, methamphetamine, pemoline, andmethylenedioxymethamphetamine.

While a subject may be addicted to a single addictive agent orbehaviour, frequently, a subject is addicted to two or more addictiveagents or behaviours. Addiction to two or more addictive agents oraddictive behaviours is referred to as polyaddiction.

2. PPARγ Agonists

Peroxisome proliferator-activated receptors (PPARs) are ligand-activatedtranscription factors of the nuclear hormone receptor superfamily. Atpresent three distinct PPAR isoforms, namely PPARα, PPARβ/δ and PPARγ,have been identified (Breidert et al., 2002; Feinstain et al. 2003). ThePPARα receptor isoform is highly expressed in the liver and kidney andit regulates fatty acid catabolism; the PPARβ/δ is ubiquitouslyexpressed and is involved in the regulation of different cellularprocesses including adipocytes, keratinocytes and oligodendrocytesdifferentiation. Finally, PPARγ receptors are predominantly expressed inadipose tissue and macrophages, where they are involved in adipocytedifferentiation, regulation of sugar and lipid homeostasis and controlof inflammatory responses (Heneka et al. 1999; Landreth and Heneka 2001;Harris and Phipps 2002).

The endogenous ligands of PPAR receptors belong to various classes ofunsaturated fatty acid compounds that include leukotrienes, retinoicacid metabolites and prostaglandins. For example, the PPARγ receptor ismainly located in the cytoplasmatic fraction and is activated by the15-deossi-Δ¹²⁻¹⁴-prostaglandin J₂ (Burstein 2005; Cernuda-Morollon, etal., 2002).

Recent studies have also shown that, in addition to various peripheraltissues, PPARδ/δ and PPARγ receptors are expressed in neurons, andolygodendrocytes (but not in astrocytes) of the central nervous system(CNS). The exact role of these receptors in the brain is not wellunderstood yet (Kainu et al. 1994).

It is known that activation of PPARγ mediates neuroprotective responsesagainst excitotoxic process and inflammatory damages (Butcher et al.2002). Activation of these receptors is also associated with improvementof cognitive performances, and has protective potential againstepileptic insults (Yu et al. 2008)

In 1997 a new class of drugs, the thiazolidinediones (TZDs), wasdeveloped in Japan, originally as anti-oxidants. Certain of thesecompounds were then approved for the clinical treatment of insulinresistance and type 2 diabetes.

At the molecular level, TDZs bind with high affinity and activate PPARγreceptors; this has been proposed as the major mechanism through whichthese molecules exert their therapeutic effects. At present, two TDZcompounds are used clinically to treat humans, pioglitazone (Actos®) androsiglitazone (Avandia®). Pioglitazone and methods for synthesizing andformulating pioglitazone and pioglitazone compositions are furtherdescribed in U.S. Pat. Nos. 4,687,777, 5,965,584 and 6,150,383, thedisclosure of each of which is hereby incorporated by reference. Othercompounds (i.e., ciglitazone, troglitazone, aleglitazar, muraglitazar,tesaglitazar, and ragaglitazar, etc.) are under development. SuitablePPARγ agonists for use in the present invention include selective PPARγagonists such as ciglitazone, troglitazone, pioglitazone, rosiglitazone,englitazone, rivoglitazone and darglidazone.

Pioglitazone hydrochloride (Actos®) binds with high affinity PPARγreceptors with agonistic properties. Pioglitazone, together withrosiglitazone (Avandia®), is an approved anti-diabetic medication thatacts primarily by decreasing insulin resistance. These two compoundsalso have positive effects on the vasculature; they lower hypertensionand are effective in atherosclerosis and stroke (Lopez-Liuchi and Meier1998; Bordet, Ouk et al. 2006). Rosiglitazone but not pioglitazone hasbeen shown to increase the risk of congestive heart failure. Recently,the efficacy of these two agents in reducing brain inflammatory damageand improving cognition in Alzheimer's patients was also documented((Landreth and Heneka 2001; Feinstein 2003); (Heneka and Landreth 2007;Kapadia, Yi et al. 2008)). Rosiglitazone binds to PPARγ receptors withhigher affinity (40 to 100 times higher) than piolitazone, butpioglitazone crosses the blood brain barrier more easily (Young, Buckleet al. 1998; Breidert, Callebert et al. 2002). This may explain whypioglitazone appears to be more effective in modulating brain PPARγreceptor effects (Maeda, Kiguchi et al. 2007). The chemical structure ofpioglitazone HCl is shown below.

An additional class of PPARγ agonists are the dual-acting PPARα/γagonists. These dual-acting PPAR agonists are a group of compounds thatactivate nuclear transcription factors. By activating both PPARα andPPARγ receptors, they simultaneously reduce atherogenic triglycerides,raise cardioprotective HDI levels, and improve insulin resistance.Examples of dual-acting PPARα/γ agonists that may be suitable for use inthe present invention include tesaglitazar, aleglitazar, muraglitazar,netoglitazone, naveglitazar, ragaglitazar, farglitazar, JTT-501,imiglitazar, chiglitazar, MK 767, LY 929, KRP-297, Compound 3q,5-substituted 2-benzoylamino-benzoic acid derivatives, O-arylmandelicacid derivatives, azaindole-α-alkyloxy-phenylpropionic acid, oximesubstituted with α-substituted-β-phenylpropionic acid derivatives withoxime, amide substituted with α-substituted-β-phenylpropionic acidderivatives, 2Alkoxydihydro cinnamate derivatives, TZD-18,α-Aryloxyphenol acetic acid derivatives, tricyclic-α-alkyloxyphenylpropionic acids, and LSN862, as described in Balakumar et al.

Other dual-acting PPARγ agonists that may be used according to thepresent invention include, but are not limited to, those that activateboth PPARδ and PPARγ. One example of such dual PPAR gamma/delta agonistis DB959 (Dara BioSciences, Inc., Raleigh, N.C., USA). DB959 is anon-thiazolidinedione (non-TZD) and does not have PPAR-alpha activity.Another dual PPARγ/δ agonist is(R)-3-{2-ethyl-4-[3-(4-ethyl-2-pyridin-2-yl-phenoxy)]-phenyl}propionic,as described in Gonzalez et al. An additional example is(R)-3-{4-[3-(4-chloro-2-phenoxy-phenoxy)-butoxy]-2-ethyl-phenyl}-propionicacid, and related compounds, as described in Xu et al.

In addition, pan-PPAR agonists that activate PPARγ, PPARα, and PPARδ maybe used in certain embodiments of the present invention. Examples ofsuch pan-PPAR agonists include bezfibrate, carbazole-derived compounds,BPR1H036, PLX-204, GW-625019, GW 677954, and indeglitazar. Otherexamples include the amphipathic 3-phenyl-7-propylbenzisoxazolesdescribed in Adams et al.

Additional PPARγ agonists that may be used according to the presentinvention include, but are not limited to, tesaglitazar, maraglitazar,peliglitazar, farglitazar, reglitazar, neviglitazar, oxeglitazar,edaglitazone, imiglitazar, and sipoglitazar, as well as those describedin the following patents and patent applications: U.S. Pat. Nos.6,294,580, 7,067,530, 6,582,738, 6,794,154, 4,812,570, 4,775,687,4,725,610, 4,582,839, and 4,572,912; and U.S. Patent ApplicationPublication Nos. US2002/006942, US2007/0299047, US2004/0077525,US2008/0045580, WO 2008/063842, the disclosures of which are herebyincorporated by reference. Examples of additional dual PPARγ agoniststhat may be used according to the present invention include, e.g., thosedescribed in U.S. Patent Application Nos. US2008/0131475, US2007/037882,US2006/0270722, US2006/0211749, US2006/0167045, and US2005/0014833, thedisclosures of which are hereby incorporated by reference. Othersuitable PPAR agonists are discussed in Shah et al, Evans et al.,Feldman et al., Kasuga et al., and Rudolph et al.

It is understood that while certain embodiments of the present inventionare described below with respect to selective PPARγ agonists, partialPPARγ agonists, dual agonists of PPARγ and PPARα, dual agonists of PPARγand PPARδ, and pan agonists of PPARγ, PPARδ, and PPARα may besubstituted for the selective PPARγ agonists to achieve otherembodiments of the present invention.

B. Methods of Treating and Preventing Addiction Using PPARγ Agonist(s)in Combination with Other Therapeutic Agents

As demonstrated in the accompanying Examples, PPARγ agonists may beeffectively used in combination with one or more additional therapeuticagents to treat or prevent addiction, including addiction to one or moreof the addictive agents described infra and compulsive or addictivebehaviour. Accordingly, the present invention includes methods oftreating or preventing an addiction, comprising providing to a subjectaddicted to, or at risk of becoming addicted to, an addictive agent oneor more PPARγ agonist(s) and one or more additional therapeuticagent(s), in which each of the PPARγ agonist(s) and the additionaltherapeutic agent(s) contribute to the effective treatment or preventionof the addiction. In one embodiment, a subject is provided with oradministered one PPARγ agonist and one additional therapeutic agent. Inanother embodiment, a subject is addicted to two or more addictiveagents. As demonstrated by the Examples below, the combination of aPPARγ agonist and another therapeutic agent may have advantageousadditive or synergistic efficacy in treating or preventing addiction orrelapse use of an addictive agent. In some embodiments, the additionalagent is another anti-addiction agent.

The PPARγ agonist and the additional therapeutic agent may beadministered at the same time (i.e., concurrently), or either may beadministered before the other (i.e., sequentially). In general, both thePPARγ agonist and the additional therapeutic agent are present in thesubject at the same time for a duration of time and at levels sufficientto provide a therapeutic benefit to the subject, i.e., in the treatmentor preventing of an addiction or the prevention of a relapse use (orreinstatement) of an addictive agent or compulsive or addictivebehaviour. The PPARγ agonist and the additional therapeutic agent may beadministered by the same or different routes of administration.Typically, the PPARγ agonist and the additional therapeutic agent areeach provided to a subject according to a standard route ofadministration of a commercially available or other pharmaceuticalcomposition. In one embodiment, the PPARγ agonist and the additionaltherapeutic agent are co-administered using a composition comprisingboth agents.

The additional therapeutic agent provided in combination with a PPARγagonist may be any therapeutic agent that contributes to an aspect ofthe effective treatment or prevention of the addiction. For example, theadditional therapeutic agent may be a drug used to treat an addiction ora drug used to alleviate side-effects associated with physiologicalwithdrawal from an addictive agent. In addition, the additionaltherapeutic agent may be any drug that affects brain serotoninneurotransmission, such as selective serotonin reuptake inhibitors(SSRIs), and tricyclic and tetracyclic serotonin and norepinephrinereuptake inhibitors (SNRIs) as described below, and serotonin agonistssuch as sumatriptan, ergonovine, dihydroergotamine and buspirone. Incertain embodiments, the additional therapeutic agent is an opioidantagonist, including mixed opioid partial agonist/antagonists, anantidepressant, an antiepileptic, an antiemetic, acorticotrophin-releasing factor-1 (CRF-1) receptor antagonist, aselective serotonin-3 (5-HT3) antagonist, a 5-HT_(2A/2C) antagonist suchas mianserin, mirtazapine and ketanserin, or a cannabinoid-1 (CB1)receptor antagonist, including but not limited to those therapeuticagents specifically described infra.

In one embodiment, the addictive agent is alcohol and the additionaltherapeutic agent is an opioid antagonist or a mixed opioidantagonist/partial agonist. In a particular embodiment, the opioidantagonist is naltrexone. In another embodiment, the mixed opioidpartial agonist/antagonist is buprenorphine. In a particular embodiment,the PPARγ agonist is pioglitazone and the additional therapeutic agentis naltrexone or buprenorphine.

In one embodiment, the addictive agent is alcohol, and the additionaltherapeutic agent is topiramate or levetiracetam. In a particularembodiment, the PPARγ agonist is pioglitazone and the additionaltherapeutic agent is topiramate or levetiracetam.

In one embodiment, the addictive agent is nicotine, and the additionaltherapeutic agent is an antidepressant. In a particular embodiment, theantidepressant is bupropion or sibutramine. In a particular embodiment,the PPARγ agonist is pioglitazone and the additional therapeutic agentis bupropion. In another particular embodiment, the PPARγ agonist ispioglitazone and the additional therapeutic agent is sibutramine.

In one embodiment, the addictive agent is nicotine, and the additionaltherapeutic agent is naltrexone.

In one embodiment, the addictive agent is cocaine, and the additionaltherapeutic agent is buprenorphine. In a particular embodiment, thePPARγ agonist is pioglitazone and the additional therapeutic agent isbuprenorphine.

In one embodiment, the addictive agent is a psychostimulant and theadditional therapeutic agent is an antidepressant. In a particularembodiment, the antidepressant is bupropion. In a particular embodiment,the PPARγ agonist is pioglitazone and the additional therapeutic agentis bupropion.

In one embodiment, the addictive agent is nicotine, and the additionaltherapeutic agent is an anti-epileptic. In a particular embodiment, theanti-epileptic is levetiracetam. Accordingly, in one embodiment, thePPARγ agonist is pioglitazone, and the anti-epileptic is levetiracetam.In another particular embodiment, the anti-epileptic agent isnaltrexone. Accordingly, in one embodiment, the PPARγ agonist ispioglitazone, and the anti-epileptic is naltrexone.

In one embodiment, the subject is addicted to two or more addictiveagents and the additional therapeutic agent is an opioid antagonist or amixed opioid partial agonist/antagonist. In a particular embodiment, themixed opioid partial agonist/antagonist is buprenorphine.

In one embodiment, the subject is addicted to both alcohol and nicotine,and the additional therapeutic agent is an anti-epileptic. In aparticular embodiment, the PPARγ agonist is pioglitazone, and theanti-epileptic is naltrexone.

In particular embodiments, a subject is provided with a combination of:pioglitazone and naltrexone; ciglitazone and naltrexone; rosiglitazoneand naltrexone; englitazone and naltrexone; rivoglitazone andnaltrexone; darglidazone and naltrexone; pioglitazone and fluoxentine;ciglitazone and fluoxentine; rosiglitazone and fluoxentine; englitazoneand fluoxentine; rivoglitazone and fluoxentine; darglidazone andfluoxentine; pioglitazone and mirtazapine; ciglitazone and mirtazapine;rosiglitazone and mirtazapine; englitazone and mirtazapine;rivoglitazone and mirtazapine; darglidazone and mirtazapine;pioglitazone and topiramate; ciglitazone and topiramate; rosiglitazoneand topiramate; englitazone and topiramate; rivoglitazone andtopiramate; darglidazone and topiramate; pioglitazone and levetiracetam;ciglitazone and levetiracetam; rosiglitazone and levetiracetam;englitazone and levetiracetam; rivoglitazone and levetiracetam;darglidazone and levetiracetam; pioglitazone and gabapentin; ciglitazoneand gabapentin; rosiglitazone and gabapentin; englitazone andgabapentin; rivoglitazone and gabapentin; darglidazone and gabapentin;piolitazone and ondansetron; ciglitazone and ondansetron; rosiglitazoneand ondansetron; englitazone and ondansetron; rivoglitazone andondansetron; darglidazone and ondansetron; pioglitazone and antalarmin;ciglitazone and antalarmin; rosiglitazone and antalarmin; englitazoneand antalarmin; rivoglitazone and antalarmin; darglidazone andantalarmin.

For treatment of alcohol addiction, combinations to be administered inaccordance with the present invention include a PPARγ agonist and anopioid agonist or a mixed opioid antagonist/partial antagonist, a PPARγagonist and an antidepressant, a PPARγ agonist and a CB1 receptorantagonist/inverse agonist, a PPARγ agonist and varenicicline, a PPARγagonist and acamprosate, and a PPARγ agonist and disulfiram.

For treatment of a psychostimulant addiction, combinations to beadministered in accordance with the present invention include, e.g., aPPARγ agonist and an antidepressant or a PPARγ agonist and a partialopioid agonist/antagonist, e.g., buprenorphine.

For treatment of nicotine addiction, combinations to be administered inaccordance with the present invention include, e.g., a PPARγ agonist andan antidepressant, a PPARγ agonist and nicotine (as a replacement, in anoral, transcutaneous or other conventional formulation), a PPARγ agonistand an opioid antagonist, a PPARγ agonist and a CB1 receptorantagonist/inverse agonist, and a PPARγ agonist and varenicicline.

For treatment of polysubstance addiction, combinations to beadministered in accordance with the present invention include, e.g., aPPARγ agonist and an opioid agonist or a mixed opioid antagonist/partialantagonist.

For treatment of gambling addiction, combinations to be administered inaccordance with the present invention include, e.g., a PPARγ agonist andand an antidepressant or a PPARγ agonist and an agent affecting dopamineneurotransmission, e.g., a direct or indirect dopamine antagonist.

The effective amount of either or both of a PPARγ agonist and anadditional therapeutic agent may be reduced when administered incombination that when either is provided alone. For example, when thePPARγ agonist and the additional therapeutic agent act additively orsynergistically, then a lower amount of the PPARγ agonist, a loweramount of the additional therapeutic agent, or lower amounts of both thePPARγ agonist or the additional therapeutic agent may be required toachieve the same therapeutic effect that would be provided by either thePPARγ agonist or the additional therapeutic agent alone.

a. Opioid Antagonists

An opioid antagonist acts on one or more opioid receptors. At leastthree types of opioid receptors, mu, kappa, and delta opioid receptors,have been reported, and opioid antagonists are generally classified bytheir effects on the opioid receptors. Opioid antagonists may antagonizecentral receptors, peripheral receptors or both. Naloxone and naltrexoneare commonly used opioid antagonist drugs that are competitive that bindto the opioid receptors with higher affinity than agonists, but that donot activate the receptors. This effectively blocks the receptor,preventing the body from responding to opiates and endorphins.

Many opioid antagonists are not pure antagonists but also produce someweak opioid partial agonist effects, and can produce analgesic effectswhen administered in high doses to opioid-naive individuals. Examples ofsuch compounds include nalorphine, and levallorphan. However, theanalgesic effects from these drugs are limited and tend to beaccompanied by dysphoria, most likely due to action at the kappa opioidreceptor. Since they induce opioid withdrawal effects in people who aretaking, or have previously used, opioid full agonists, these drugs areconsidered to be antagonists.

Naloxone is one example of an opioid antagonist that has no partialagonist effects. Instead, it is a weak inverse agonist at mu opioidreceptors, and is used for treating opioid overdose.

Specific examples of opioid antagonists that may be used according tothe invention include alvimopan, binaltorphimine, buprenorphine,cyclazocine, cyclorphan, cypridime, dinicotinate, beta-funaltrexamine,levallorphan, methylnaltrexone, nalbuphine, nalide, nalmefene,nalmexone, nalorphine, nalorphine dinicotinate, naloxone, naloxonazine,naltrendol, naltrexone, naltrindole, oxilorphan, and pentazocine.

b. Antidepressents

Antidepressents are drugs used to treat depression. The threeneurotransmitters believed to be involved in depression are serotonin,dopamine, and norepinephrine. Certain types of antidepressants increasethe levels of one or more of these neurotransmitters in the brain byblocking their reabsorption.

Several different classes of antidepressants have been identified,including selective serotonin reuptake inhibitors (SSRIs), tricyclic andtetracyclic serotonin and norepinephrine reuptake inhibitors (SNRIs),norepinephrine reuptake inhibitors (NRIs), norepinephrine and dopaminereuptake inhibitors (NDRIs), azaspirones, monoamine oxidase inhibitors(MAOIs), and atypical antidepressants.

SSRIs include, e.g., cericlamine, citalopram, clomipramine,cyanodothiepin, dapoxetine, duloxetine, escitalopram, femoxetine,fluoxetine, fluvoxamine, ifoxetine, imipramine, indalpine, indeloxazine,litoxetine, lofepramine, mianserine, milnacipran, mirtazapine,nefazadone, nortriptyline, paroxetine, sertraline, sibutramine,tomoxetine, trazodone, venlafaxine, and zimeldine.

Amitriptyline, amoxapine, butriptyline, clomipramine, demexiptiline,desipramine, dibenzepin, dimetacrine, dothiepin, doxepin, imipramine,iprindole, lofepramine, maprotiline, melitracen, metapramine, mianserin,mirtazpine, nortriptyline, propizepine, protriptyline, quinupramine,setiptiline, tianeptine, and trimipramine are all tricyclic andtetracyclic antidepressants.

SNRIs include, e.g., amoxapine, atomoxetine, bicifadine, desipramine,desvenlafaxine, duloxetine, maprotiline, milnacipran, nefazodone,reboxetine, sibutramine, and venlafaxine.

Nisoxetine, nortriptyline, reboxetine, talsupram, and tomoxetine are allexamples of NRIs.

NDRIs include, e.g., bupropion, hydroxybupropion, and tesofensine.

Azaspirones include, e.g., buspirone, gepirone, ipsapirone,tandospirone, and tiaspirone. Buspirone is an anxiolytic (partialagonist at 5-HT1 autoreceptors) that may be provided with ananti-depressant such as an SSRI.

Specific MAOIs include, e.g., amiflamine, brofaromine, clorgyline,alpha-ethyltryptamine, iproclozide, iproniazid, isocarboxazid,mebanazine, moclobemide, nialamide, pargyline, phenelzine, pheniprazine,pirlindole, safrazine, selegiline, toloxatone, and tranlcypromine.

Atypical antidepressants include, e.g., amesergide, amineptine,benactyzine, bupropion, clozapine, fezolamine, levoprotiline, lithium,medifoxamine, mianserin, minaprine, olanzapine, oxaflozane, oxitriptan,rolipram, teniloxazine, tofenacin, trazodone, tryptophan, andviloxazine.

c. Antiepileptics

The anticonvulsants, also called anti-epileptic drugs (AEDs) are adiverse group of drugs used in prevention of the occurrence of epilepticseizures and bipolar disorders. AEDs suppress the rapid and excessivefiring of neurons that begins a seizure and/or prevents the spread ofthe seizure within the brain and offer protection against possibleexcitotoxic effects that may result in brain damage. Manyanticonvulsants block sodium channels, calcium channels, AMPA receptors,or NMDA receptors.

Anti-epileptic agents include, but are not limited to, benzodiazepines,barbituates, valproates, GABA agents, iminostilibenes, hydantoins, NMDAantagonists, sodium channel blockers and succinamides.

Benzodiazepines include, e.g., alprazolam, chlordiazepoxide,cholrazepate, clobazam, clonazepam, diazepam, halazapam, lorazepam,oxazepam, and prazepam.

Barbiturates used as anti-epileptics include, e.g., amobarbital,mepobarbital, methylphenobarbital, pentobarbital, phenobarbital, andprimidone.

Valproates used as anti-epileptics include, e.g., sodium valporate,valproic acid, valproate sem isodium, and valpromide.

Anti-epileptic GABA agents include, e.g., gabapentin, pregabalin,losigamone, pregabalin, retigabine, rufinamide, and vigabatrin.

Carbamazepine and oxcarbazepine are examples of iminostilbenes.

Hydantoins include, e.g., fosphenytoin sodium, mephenytoin, andphenytoin sodium.

NMDA antagonists such as harkoseramide are used as anti-epileptics.

Sodium channel blockers such as lamotrigine are also anti-epilepticagents.

Succinimides include, e.g., ethosuximide, methsuximide, andphensuximide.

Other anti-epileptic drugs include acetazolamide, briveracetam, CBDcannabis derivative, clomthiazole edisilate, divalproex sodium,felbamate, isovaleramide, lacosamide, lamotrigine, levetiracetam,methanesulphonamide, talampanel, tiagabine, topiramate, safinamide,seletracetam, soretolide, stiripentol, sultiam, valrocemide, andzonisamide.

d. Antiemetics

Anti-emetics are drugs effective against vomiting and nausea.Anti-emetics are typically used to treat motion sickness and the sideeffects of opioid analgesics, general anaesthetics, and chemotherapy.

Classifications of anti-emetics include, e.g., 5-hydroxytryptamine 3(5-HT3) receptor antagonists, histamine receptor antagonists, dopaminereceptor antagonists, muscarinic receptor antagonists, acetyl cholinereceptor antagonists, cannabinoid receptor antagonists, limbic systeminhibitors, NK-1 receptor antagonists, corticosteroids, tachykininantagonists, GABA agonists, cannabinoids, benzodiazepines,anticholinergics, and substance P inhibitors.

5-HT3 receptor antagonists include, e.g., alosetron, azasetron,bemesetron, cilansetron, dolasetron, granisetron, indisetron, itasetron,ondansetron, palonosetron, propisetron, ramosetron, renzapride,tropisetron, and zatosetron.

Coritcosteroid anti-emetics include dexamethasone andmethylprednisolone.

Lymbic system inhibitors include alprazolam, lorazepam, and midazolam.

Dopamine receptor antagonists include diphenhydramine, dronabinol,haloperidol, metoclopramide, and prochlorperazine.

NK-1 receptor antagonists used as an anti-emetic include aprepitant andmorpholine, and an example of a GABA agonist is propofol.

Thiethylperazine is a type of histamine receptor antagonist.

Cannabinoid receptor antagonists used as anti-emetics includedronabinol, nabilone, rimonabant, tanarabout, and tetrahydrocannabinol.

Examples of other anti-emetics include acetylleucine, monoethanolamine,alizapride, benzquinamide, bietanautine, bromopride, buclizine,chlorpromazine, clebopride, cyclizine, dimenhydrinate, dipheniodol,domperidone, dranisetron, meclizine, methalltal, metopimazine,oxypendyl, pipamazine, piprinhydrinate, scopolamine, thioproperzaine,and trimethobenzamide.

e. Cannabinoid Receptor Antagonists

The cannabinoid receptors are a class of the G-protein coupled receptorsuperfamily. Their ligands are known as cannabinoids. There arecurrently two known subtypes, CB1 which is expressed mainly in thebrain, but also in the lungs, liver, and kidney, and CB2, which ismainly expressed in the immune system and in hematopoietic cells. It isalso believed that there are novel cannabinoid receptors that is,non-CB1 and non-CB2, which are expressed in endothelial cells and in theCNS. Cannabinoid receptor antagonists may be selective for either theCB1 or CB2 receptor. The present invention contemplates the use ofeither or both CB1 and CB2 receptor antagonists.

Addictive agents (e.g., alcohol, opiates, Delta(9)-tetrahydrocannabinol(Delta(9)-THC) and psychostimulants, including nicotine) elicit avariety of chronically relapsing disorders by interacting withendogenous neural pathways in the brain. In particular, they share thecommon property of activating mesolimbic dopamine brain reward systems,and virtually all abused drugs elevate dopamine levels in the nucleusaccumbens. Cannabinoid-1 (CB1) receptors are expressed in this brainreward circuit and modulate the dopamine-releasing effects ofDelta(9)-THC and nicotine.

Rimonabant (SR141716), a CB1 receptor antagonist, blocks both thedopamine-releasing and the discriminative and rewarding effects ofDelta(9)-THC in animals. Although CB1 receptor blockade is generallyineffective in reducing the self-administration of cocaine in rodentsand primates, it reduces the reinstatement of extinguishedcocaine-seeking behaviour produced by cocaine-associated conditionedstimuli and cocaine priming injections. Similarly, CB1 receptor blockadeis effective in reducing nicotine-seeking behaviour induced byre-exposure to nicotine-associated stimuli. In human clinical trials,rimonabant was shown to block the subjective effects of Delta(9)-THC inhumans and prevents relapse to smoking in ex-smokers.

Other examples of cannabinoid receptor CB1 antagonists include SR141716A(rimonabant), rosanabant, taranabant and CP-945598.

C. Methods of Treating and Preventing Relapse

Relapse use, or reinstatement, refers to the process of returning to theuse of alcohol or another addictive agent or the practice of anaddictive behaviour after a period of abstinence from, or limited orreduced use of, an addictive agent or practice of an addictivebehaviour. In certain situations, relapse use of an addictive agentrefers to the return to use of an addictive agent by a subject who hasundergone physical withdrawal from the addictive agent. Typically, thesubject will have undergone physical withdrawal from the addictive agentduring a period of non-use or limited or reduced use of the addictiveagent. In one embodiment, relapse use occurs in a subject who haspreviously undergone a treatment regime with an effective amount of ananti-addiction agent to reduce or eliminate use of an addictive agent,but who is no longer using an effective amount of the anti-addictionagent. Anti-addictive agents include any and all agents used to treat orprevent addiction or withdrawal symptoms.

Alcoholism, like many other addictions, is a chronic relapsing disordercharacterized by high recidivism rates. Two major factors triggeringrelapse behaviour are stress and environmental conditioning experiences(O'Brien et al. 1997; Monti et al. 1993; Shaham et al. 1995), whichprobably facilitate relapse to alcohol-seeking via distinct brainmechanisms. For example, activation of the mesolimbic dopamine systemvia an opioid-dependent mechanism (or via direct alterations in dopaminetransmission in the basolateral nucleus of amygdala) seems to mediatethe effect of drug-associated cues (Liu and Wiess 2002; Ciccocioppo etal. 2001), and, extrahypothalamic CRF within the bed nucleus of thestria terminalis and median raphe nucleus is likely to mediatestress-induced reinstatement of drug-seeking behaviour (Erb et al 1998;Shaham et al. 1995; Lê et al. 2000).

Several lines of evidence suggest that molecular mechanisms underlyingrelapse to addiction are common to different classes of drugs of abuse.Drug craving and loss of control over drug taking behaviour associatedto relapse are under the direct influence of stress and environmentalconditioning stimuli; the two major factors affecting resumption to druguse.

Chronic drug abuse produces neuroadaptive changes not only withinsystems implicated in the acute reinforcing effects of ethanol, but alsowithin other motivational systems, notably brain stress-regulatorymechanisms. Stress has an established role in the initiation andmaintenance of drug abuse, and is a major determinant of relapse inabstinent individuals (Brown et al. 1995; Marlatt et al. 1985; McKay etal. 1995; Wallace 1989). The significance of stress in drug-seekingbehaviour has also been amply documented in the animal literature.Physical, social, and emotional stress can facilitate acquisition orincrease self-administration of cocaine (Goeders et al. 1995; Haney etal. 1995; Ramsey and VanRee 1993; Ahmed and Koob 1997), heroin, (Shahamand Stewart 2004), and ethanol (Nash et al. 1998; Mollenauer et al.1993; Blanchard et al. 1987; Higley et al. 1991)) in rodents andnonhuman primates. Stressful stimuli have also been shown to elicitreinstatement of cocaine, heroin, and ethanol-seeking behaviour indrug-free animals following extinction (Ahmed and Koob 1997; Shaham1993; Shaham and Stewart 1995; Ie et al. 1998) and these findingsprovide experimental support for a role of stress in relapse.

Traditionally, stress-related drug-seeking behaviour has been thought tobe mediated via activation of the hypothalamic-pituitary-adrenal (HPA)axis. However, growing evidence suggests that the non-neuroendocrinecorticotropin-releasing factor (CRF) system in the central nucleus ofthe amygdala (CeA) may play a significant independent role in theregulation of addictive behaviour associated with stress. The CeA isrich in CRF immunoreactive cell bodies, terminals, and receptors, andthis neuronal CRF system has been implicated in the mediation ofbehavioural and emotional responses to stressful stimuli (Dunn andBerridge 1990; Koob et al. 1994). For example, immobilization stresselevates extracellular CRF levels in the CeA (Merlo Pich et al. 1995;Merali et al. 1998) while intra-CeA injection of the CRF receptorantagonist, α-helical CRF9-41, reduces behavioural signs of anxietyproduced by social and environmental stressors (Heinrichs et al. 1992;Swiergiel et al. 1993). Anxiety and stress-like symptoms are central todrug and alcohol withdrawal syndromes. Considering the evidence on arole of CRF neurons in the CeA in the regulation of emotional andanxiogenic effects of stress, it is likely that anxiogenic andstress-like consequences of withdrawal from drugs of abuse may bemediated by the CRF system in the CeA as well.

Changes in the regulation of the activity of the CRF system within theCeA may represent a critical neuroadaptive mechanism responsible for thedevelopment of dependence and compulsive drug-seeking behaviour.

The data discussed above identify neuroadaptive changes in braincircuitries and perturbations in stress systems as an important elementin compulsive drug-seeking behaviour and dependence. Another importantfactor in the long-lasting addictive potential of drugs of abuse is theconditioning of their rewarding actions with specific environmentalstimuli. Environmental cues repeatedly associated with the subjectiveeffects of drugs of abuse including alcohol can evoke drug craving(Childress et al. 1988; Ehrman et al. 1992; Monti et al. 1993; Pomerleauet al. 1983; Stormark et al. 1995) or elicit automatic behaviouralresponses (Miller and Gold 1994; Tiffany and Carter 1998) thatultimately may lead to relapse. Learned responses to drug-relatedstimuli may, therefore, contribute critically to the high rates ofrelapse associated with cocaine and other drug addiction.

Data from operant response-reinstatement models developed to investigatedrug-seeking behaviour associated with exposure to drug-relatedenvironmental cues in rats indicate that discriminative stimulipredictive of cocaine (Weiss et al. 2000), ethanol (Katner et al. 1999;Katner and Weiss 1999), or heroin (Gracy et al. 2000) availabilityreliably elicit strong recovery of extinguished drug-seeking behaviourin the absence of further drug availability. The response-reinstatingeffects of these stimuli show remarkable resistance to extinction withrepeated exposure and, in the case of cocaine, can still be observedafter several months of forced abstinence. Additionally, in the case ofethanol, drug-seeking behaviour induced by ethanol-predictivediscriminative stimuli was found to be enhanced in geneticallyalcohol-preferring P rats compared to Alcohol Nonpreferring (NP) andnonselected Wistar rats (Weiss and Ciccocioppo 1999). This observationdemonstrates that genetic predisposition toward heightened ethanolintake is reflected also by a greater susceptibility to the motivatingeffects of ethanol cues (i.e., enhanced drug-seeking under conditionswhere behaviour is not directly reinforced by ethanol itself). Together,these findings strongly support the hypothesis that learned responses todrug-related stimuli are a significant factor in long-lastingvulnerability to relapse.

In humans, relapse risk involves multiple determinants that are likelyto interact. For example, exposure to drug cues may augmentvulnerability to relapse imparted by protracted withdrawal symptomsresulting from neuroadaptive changes in dependent individuals.Interactive effects exacerbating relapse risk may also exist between themotivating effects of stress and drug-related cues. Recent workaddressing these issues has confirmed that additive interactions betweenthe response-reinstating effects of ethanol-associated cues and stresscan indeed be demonstrated, and that these effects are enhanced in ratswith a history of ethanol dependence (Liu and Weiss 2000).

In experimental laboratories, reinstatement of drug seeking is obtainedwith administration of the α-2 adrenoreceptor antagonist yohimbine,which, increasing brain noradrenaline cell firing and release, acts as apharmacological stressor. Footshock stress and yohimbine-inducedreinstatement of drug-seeking behaviours both represent validexperimental models to investigate stress-induced alcohol relapse (Leeet al. 2004; Lê et al. 2000).

As shown in the accompanying Examples, PPARγ agonists significantlyreduce stress-induced relapse use of an addictive agent (Example 5). Inaddition, in human patients, pioglitazone, a TZD, consistently reducedOCDS score (Example 22). Obsession for alcohol and the urge to drink(which are measured by OCDS scale) are the major predictors of relapse.These data indicate, therefore, that pioglitazone has anti-relapseproperties.

Interestingly, the results showed that pioglitazone did notsignificantly prevent relapse elicited by conditioning factors.Interestingly, various reports have shown that the nonselective opiatereceptor antagonist naltrexone reduces the urge to drink elicited bypresentation of alcohol cues in human alcoholics (Monti et al. 1993) anddecreases the efficacy of an alcohol cue to reinstate extinguishedresponding at a previously drug-paired lever in rats (Katner et al.1999). However, naltrexone does not reduce relapse behaviour elicited bystress ((Le A. D. Psychopharmacology 1998).

These findings suggest that the use of a combination of pioglitazone andnaltrexone should result in a synergistic action to reduce relapsebehaviour elicited by both stress and conditioning factors.

Accordingly, the present invention provides treatment methods and drugcombinations that protect individuals from the effects of more than asingle environmental risk factor (i.e., stress and environmentalconditioning factors).

In one embodiment, the present invention provides a method of treatingor preventing stress-induced relapse use of an addictive agent,comprising providing a PPARγ agonist to a subject who has undergonephysiological withdrawal from an addictive agent.

In a related embodiment, the invention includes a method of treating orpreventing relapse use of an addictive agent or practice of an addictiveor compulsive behaviour, comprising providing an effective amount of aperoxisone proliferator-activated receptor gamma (PPARγ agonist) to asubject who previously reduced or eliminated use of an addictive agentor practice of an addictive or compulsive behaviour in response toexposure to an effective amount of another anti-addiction treatment,wherein the subject is no longer exposed to an effective amount of theanti-addiction treatment. The anti-addiction treatment may be ananti-addiction drug or may be a non-pharmacologic therapy such ascounseling, psychotherapy or hypnosis therapy. The relapse use may betriggered by stress.

In certain embodiments, the subject is no longer exposed to an effectiveamount of an anti-addiction agent because the subject has becometolerant to the agent, such that the blood plasma concentration of theanti-addiction agent that was previously effective in treating theaddiction is no longer effective. In other embodiments, the subject isno longer exposed to an effective amount of an anti-addiction agentbecause the subject is now exposed to a lower blood plasma concentrationof the anti-addiction agent, and this lower blood plasma concentrationis not effective.

In certain embodiments of the methods of the present invention, thesubject has undergone a period of abstinence from, or limited or reduceduse of, the addictive agent or practice of the addictive or compulsivebehaviour. This period of abstinence or limited or reduced use may be,e.g., at least 24 hours, at least 48 hours, at least 3 days, at least 5days, at least one week, at least 2 weeks, at least 1 month, at least 2months, at least 4 months, at least 6 months, at least 9 months, atleast one year, at least 2 years, or at least 5 years.

In another embodiment, the present invention includes a method oftreating or preventing relapse use of an addictive agent, comprisingproviding a PPARγ agonist and an opioid antagonist to a subject who hasundergone physiological withdrawal from the addictive agent.

In a further embodiment, the present invention includes a method oftreating or preventing relapse use of an addictive agent, comprisingproviding a PPARγ agonist and a CB1 antagonist, e.g., disulfiram,topiramate, levetiracetam, SSRIs, or ondansetron, to a subject who hasundergone physiological withdrawal from the addictive agent.

In particular embodiments, the relapse use is triggered by stress, anenvironmental conditioning factor, or both. Examples of suitable PPARγagonists are TDZs, such as pioglitazone, etc. One example of a suitableopioid receptor antagonist is naltrexone.

While the methods of the present invention may be practiced in subjectsaddicted to a single addictive agent, they may also be used in subjectsaddicted to two or more addictive agents. Similarly, while these methodsmay be used to prevent relapse use of the addictive agent from which thesubject has undergone withdrawal, they may also be adapted to preventrelapse use or the commencement of use of an addictive agent differentthan the one from which the subject has undergone physiologicalwithdrawal.

D. Methods of Reducing Withdrawal Symptoms and TreatingDepression/Anxiety

Withdrawal, also known as withdrawal/abstinence syndrome, refers to thecharacteristic signs and symptoms that appear when a drug or addictiveagent that causes physical dependence is regularly used for a long timeand then suddenly discontinued or decreased in dosage. Withdrawalsymptoms can vary significantly among individuals, but there are somecommonalties. Brain dysfunction associated with withdrawal is oftencharacterized by depression, anxiety and craving, and, if extreme, canhelp drive the individual to continue the drug despite significantharm—the definition of addiction—or even to suicide.

Increased heart rate and/or blood pressure, sweating, and tremors arecommon signs of withdrawal. More serious symptoms such as confusion,seizures, and visual hallucinations indicate a serious emergency and theneed for immediate medical care. Alcohol, opiates, benzodiazepines, andbarbiturates are the only commonly abused substances that can be fatalin withdrawal. Abrupt withdrawal from other drugs, such as nicotine orpsychostimulants, can exaggerate mild to moderate neurotoxic sideeffects due to hyperthermia and generation of free radicals, butlife-threatening complications are very rare.

As demonstrated in the accompanying Examples, PPARγ agonists reducewithdrawal symptoms (Example 21). In addition, they decreased anxietyand depression, which is also associated with withdrawal (Example 22).These data demonstrate that PPARγ agonists may be successfully used toreduce withdrawal symptoms, including depression and anxiety, thusmaking withdrawal easier for subjects and encouraging them to completethe withdrawal process.

The present invention includes a method of reducing one or morewithdrawal symptoms associated with reduced or discontinued use of anaddictive agent, comprising providing an effective amount of aperoxisome proliferator-activated receptor gamma (PPARγ) agonist to asubject undergoing physiological withdrawal from an addictive agent. Inparticular embodiments, the addictive agent is alcohol, an opioidagonist, such as morphine, or nicotine. In certain embodiments, thePPARγ agonist is a TZD, e.g., pioglitazone.

The PPARγ agonist may be provided to the subject before the subjectbegins withdrawal and/or during the withdrawal process. In a relatedmethod, a subject is provided with a PPARγ agonist over a period of timeduring which the subject uses a reduced amount of an addictive agent.For example, the subject may begin using a PPARγ agonist at the sametime that they cease using or begin using a reduced amount of anaddictive agent. In one embodiment, the subject uses a step-wise reducedamount of an addictive agent at the same time as a PPARγ agonist, untilphysical withdrawal is completed. The subject may then discontinue useof the PPARγ agonist or continue use of the PPARγ agonist to preventrelapse. Therefore, in related embodiments, the present inventioncontemplates delivering an addictive agent in combination with a PPARγagonist, e.g., to reduce the likelihood of developing addiction, or toreduce withdrawal symptoms. In particular embodiments, the PPARγagonist, e.g., pioglitazone, is delivered in combination with nicotineor an opioid agonist. The PPARγ agonist and the addictive agent may bedelivered separately or in a single formulation or via a single deliverymeans. For example, both nicotine and a PPARγ agonist, such aspioglitazone, may be delivered via a transdermal patch, an oral lozenge,or a chewing gum delivery system. Transdermal patches, oral lozenges,and chewing gum containing nicotine are frequently used for the deliveryof nicotine to subjects attempting to reduce nicotine use. By includinga PPARγ agonist in combination with the nicotine in the transdermalpatch, lozenge, or chewing gum, it is believed that the subject willsuffer less nicotine withdrawal symptoms. In addition, this mayfacilitate greater compliance and more rapid reduction in nicotine use.The same principal applies to other addictive agents, including, e.g.,opioid agonists. In addition, intranasal spray, an atomizer, or aninhalation device may be used to deliver nicotine or another addictiveagent in combination with a PPAR agonist, such as a PPARγ agonist likepioglitazone.

In one particular embodiment, the addictive agent is nicotine, and thesubject reduces or discontinues use of nicotine over a period of timeduring which the subject is provided with a PPARγ agonist, such as aTZD, e.g., pioglitazone, alone or in combination with anothertherapeutic agent. PPARγ agonist and nicotine combinations in the formof a transdermal patch, lozenge, chewing gum or other delivery vehiclemay be prescribed in reducing dosages, or decreasing dosages may bekitted together, to permit tapering off of use of the drug product.

E. Pharmaceutical Compositions, Routes of Administration, Unit DosageForms, and Kits

The present invention has established the efficacy of using combinationsof a PPARγ agonist, e.g., a TZD such as pioglitazone, in combinationwith one or more additional therapeutic agents, such as opioidantagonists, antidepressents, antiepileptics, antiemetics, and CB1receptor antagonists. Thus, the present invention further includescompositions comprising one or more PPARγ agonists and one or moreadditional therapeutic agents, such as opioid antagonists, mixed opioidantagonists/partial agonist, antidepressents, antiepileptics,antiemetics, CRF1 receptor antagonists and CB1 receptor antagonists.

The present invention has also established the efficacy of using a PPARγagonist, e.g., a TZD such as pioglitazone, in combination with anaddictive therapeutic agent, e.g., to prevent or reduce the likelihoodthat a subject treated with an addictive therapeutic agent will becomeaddicted to it. Examples of addictive therapeutic agent include, but arenot limited to, therapeutic opioid agonists, such as pain medications.Thus, the present invention includes methods involving contacting asubject with both an addictive therapeutic agent and one or more PPARγagonists, as well as pharmaceutical compositions, and unit dosage formsthereof, comprising one or more PPARγ agonists and one or more addictivetherapeutics agents, e.g., an opioid agonist such as, e.g., oxycodone orhydrocodone. In particular embodiments, the PPARγ agonist ispioglitazone, and the addictive therapeutic agent is oxycodone, or thePPARγ agonist is pioglitazone, and the addictive therapeutic agent ishydrocodone.

The present invention has further established the efficacy of using aPPARγ agonist, e.g., a TZD such as pioglitazone, in combination with anaddictive agent, e.g., to prevent or reduce withdrawal symptoms as asubject stops use or reduces use of the addictive agent. Examples ofsuch addictive agent include, but are not limited to, therapeutic opioidagonists, such as pain medications, nicotine, and alcohol. Thus, thepresent invention includes methods involving contacting a subject withboth an addictive agent and one or more PPARγ agonists, as well aspharmaceutical compositions, and unit dosage forms thereof, comprisingone or more PPARγ agonists and one or more addictive agents, e.g., anopioid agonist such as, e.g., oxycodone or hydrocodone, nicotine, oralcohol. In particular embodiments, the PPARγ agonist is pioglitazone,and the addictive therapeutic agent is nicotine.

In particular embodiments, the composition comprises one PPARγ agonistand one additional therapeutic agent. In one particular embodiment, apharmaceutical composition comprises a TZD and one additionaltherapeutic agent. In certain embodiments, the additional therapeuticagent is an opioid antagonist or a mixed opioid antagonist/partialagonist. In one embodiment, the opioid antagonist is naltrexone. Inanother embodiment, the mixed opioid partial agonist/antagonist isbuprenorphine. In certain embodiments, the additional therapeutic agentis an antidepressant. In a particular embodiment, the antidepressant isbupropion. In certain embodiments, the additional therapeutic agent isan antiepileptic, an antiemetic, or an opioid antagonist or a mixedopioid partial agonist/antagonist. In further embodiments, theadditional therapeutic agent is an opioid agonist.

In particular embodiments, the present invention provides a compositioncomprising both an addictive agent, such as nicotine, an opioid agonist,or alcohol, and a PPAR agonist, e.g., a TZD such as pioglitazone. Suchcompositions may be in any suitable form. For instance, a compositioncomprising both nicotine and a PPAR agonist, such as pioglitazone, maybe, e.g., a transdermal patch comprising both agents, a lozengecomprising both agents, or a chewing gum comprising both agents.Examples of transdermal patches comprising a PPARγ agonist are providedin U.S. Pat. No. 6,011,049. Examples of a PPARγ agonist delivered usingpatches, lozenges, or chewing gum are described in PCT Publication Nos.WO2007/075847, WO03/026586, and WO 05/107713, each of which isincorporated by reference with respect to its description of PPARγagonist formulations, dosages, and delivery methods.

Dosages of PPAR agonist present in such a combination may be readilydetermined depending upon the route of administration, in order toprovide a suitable dosage over the course of administration. In oneembodiment wherein pioglitazone is administered in combination withnicotine, e.g., both present in a transdermal patch, the dosage ofpioglitazone may be, e.g., between 5-45 mg per day, between 5-15 mg perday, between 10-15 mg per day, or about 5, about 10, or about 15 mg perday. In certain embodiments, the dosage of pioglitazone is less than orequal to 15 mg per day or less than or equal to 10 mg per day. Incertain embodiments, glitazones are administered at doses from about 5mg to about 2500 mg per day, and more typically from about 50 mg toabout 1500 mg per day. In one embodiment, the glitazone is troglitazone,and it is used at doses from about 100 mg to about 1000 mg per day. Inanother embodiment, the glitazone is rosiglitazone, and it is used atdoses of about 5 mg to about 10 mg per day. In another embodiment, theglitazone is pioglitazone, and it is used at doses of about 50 mg toabout 200 mg per day.

In particular embodiments of pharmaceutical compositions, and unitdosage forms thereof, comprising both a PPAR agonist and an opioidagonist, the PPAR agonist is a PPARγ agonist, e.g., aTZD. In certainembodiments, the PPARγ agonist is pioglitazone, rosiglitazone,ciglitazone, troglitazone, englitazone, rivoglitazone, or darglidazone.In particular embodiments, the opioid agonist is a phenanthrene, aphenylheptylamine, or a phenylpiperidine. In certain embodiments, theopioid agonist is alfentanil, allylprodine, alphaprodine, anileridine,apomorphine, benzylmorphine, beta-hydroxy 3-methylfentanyl, bezitramide,carfentanil, clonitazene, codeine, desomorphine, dextromoramide,diacetylmorphine (heroin), diampromide, dihydrocodeine,dihydroetorphine, dihydromorphine, dimenoxadol, dimepheptanol,dimethylthiambutene, dioxaphetylbutyrate, dipipanone, eptazocine,ethoheptazine, ethylmethylthiambutene, ethylmorphine, etonitazene,etorphine, fentanyl, hydrocodone, hydromorphone, hydroxypethidine,isomethadone, ketobemidone, LMM, levorphanol, levophenacylmorphan,lofentanil, meperidine, metapon, metazocine, methadone, methadylacetate, metopon, morphine, myrophine, narceine, nicomorphine,norlevorphanol, normethadone, normorphine, norpipanone, opium,oxycodone, oxymorphone, papaverine, phenadoxone, phenomorphan,phenoperidine, piminodine, piritramide, propheptazine, promedol,properidine, propoxyphene, remifentanil, sufentanil, thebaine, tildine,or tramadol, or any combination thereof.

In various embodiments, the composition comprises: pioglitazone andnaltrexone; ciglitazone and naltrexone; rosiglitazone and naltrexone;englitazone and naltrexone; rivoglitazone and naltrexone; darglidazoneand naltrexone; pioglitazone and fluoxentine; ciglitazone andfluoxentine; rosiglitazone and fluoxentine; englitazone and fluoxentine;rivoglitazone and fluoxentine; darglidazone and fluoxentine;pioglitazone and mirtazapine; ciglitazone and mirtazapine; rosiglitazoneand mirtazapine; englitazone and mirtazapine; rivoglitazone andmirtazapine; darglidazone and mirtazapine; pioglitazone and topiramate;ciglitazone and topiramate; rosiglitazone and topiramate; englitazoneand topiramate; rivoglitazone and topiramate; darglidazone andtopiramate; pioglitazone and levetiracetam; ciglitazone andlevetiracetam; rosiglitazone and levetiracetam; englitazone andlevetiracetam; rivoglitazone and levetiracetam; darglidazone andlevetiracetam; pioglitazone and gabapentin; ciglitazone and gabapentin;rosiglitazone and gabapentin; englitazone and gabapentin; rivoglitazoneand gabapentin; darglidazone and gabapentin; piolitazone andondansetron; ciglitazone and ondansetron; rosiglitazone and ondansetron;englitazone and ondansetron; rivoglitazone and ondansetron; darglidazoneand ondansetron; pioglitazone and antalarmin; ciglitazone andantalarmin; rosiglitazone and antalarmin; englitazone and antalarmin;rivoglitazone and antalarmin; darglidazone and antalarmin.

In additional embodiments, the composition comprises pioglitazone andcodeine, pioglitazone and morphine, pioglitazone and noscapapine,pioglitazone and hydrocodone, pioglitazone and hydromorphone,pioglitazone and oxycodone, pioglitazone and tramadol, pioglitazone andfentanyl, pioglitazone and propoxyphene, pioglitazone and methadone,ciglitazone and codeine, ciglitazone and morphine, ciglitazone andnoscapapine, ciglitazone and hydrocodone, ciglitazone and hydromorphone,ciglitazone and oxycodone, ciglitazone and tramadol, ciglitazone andfentanyl, ciglitazone and propoxyphene, ciglitazone and methadone,rosiglitazone and codeine, rosiglitazone and morphine, rosiglitazone andnoscapapine, rosiglitazone and hydrocodone, rosiglitazone andhydromorphone, rosiglitazone and oxycodone, rosiglitazone and tramadol,rosiglitazone and fentanyl, rosiglitazone and propoxyphene,rosiglitazone and methadone, englitazone and codeine, englitazone andmorphine, englitazone and noscapapine, englitazone and hydrocodone,englitazone and hydromorphone, englitazone and oxycodone, englitazoneand tramadol, englitazone and fentanyl, englitazone and propoxyphene,englitazone and methadone, rivoglitazone and codeine, rivoglitazone andmorphine, rivoglitazone and noscapapine, rivoglitazone and hydrocodone,rivoglitazone and hydromorphone, rivoglitazone and oxycodone,rivoglitazone and tramadol, rivoglitazone and fentanyl, rivoglitazoneand propoxyphene, rivoglitazone and methadone, darglidazone and codeine,darglidazone and morphine, darglidazone and noscapapine, darglidazoneand hydrocodone, darglidazone and hydromorphone, darglidazone andoxycodone, darglidazone and tramadol, darglidazone and fentanyl,darglidazone and propoxyphene, or darglidazone and methadone. In aparticular embodiment, the composition comprises both pioglitazone andoxycodone.

The compositions of the present invention may be administered to asubject as a pharmaceutical composition or formulation. In particularembodiments, pharmaceutical compositions of the present invention may bein any form which allows for the composition to be administered to asubject. For example, the composition may be in the form of a solid,liquid or gas (aerosol). In particular embodiments, the compositions maybe provided using drug delivery systems suitable for delivering by anyappropriate route of administration, including, e.g., intranasal spraysor inhalation devices. Typical routes of administration include, withoutlimitation, oral, topical, parenteral, transdermal, intranasal,inhalation, sublingual, rectal, vaginal, and intranasal. The termparenteral as used herein includes subcutaneous injections, intravenous,intramuscular, epidural, intrasternal injection or infusion techniques.

Pharmaceutical compositions used according to the present inventioncomprise a PPAR agonist (e.g., a PPARg agonist), another therapeuticagent, and a pharmaceutically acceptable diluent, excipient, or carrier.“Pharmaceutically acceptable carriers” for therapeutic use are wellknown in the pharmaceutical art, and are described, for example, inReminqtons Pharmaceutical Sciences, Mack Publishing Co. (A. R. Gennaroedit. 1985). For example, sterile saline and phosphate-buffered salineat physiological pH may be used. Preservatives, stabilizers, dyes andeven flavoring agents may be provided in the pharmaceutical composition.For example, sodium benzoate, sorbic acid and esters of p-hydroxybenzoicacid may be added as preservatives. Id. at 1449. In addition,antioxidants and suspending agents may be used. Id. The compositions maycontain common excipients and carriers such as starch, sucrose, talc,gelatin, methylcellulose, and magnesium stearate.

Pharmaceutical compositions of the invention are generally formulated soas to allow the active ingredients contained therein to be bioavailableupon administration of the composition to a subject. Compositions thatwill be administered to a subject may take the form of one or moredosage units, where for example, a tablet, capsule or cachet may be asingle dosage unit, and a container comprising a combination of agentsaccording to the present invention in aerosol form may hold a pluralityof dosage units. The compositions may be made for oral administration,for instance as tablets or capsules, but also may be in the form ofaqueous suspensions or solutions, suppositories, slow release forms, forexample employing an osmotic pump, transdermal patch, or the like. Incertain embodiments, a transdermal patch may comprise a unit dosage formof a PPARγ agonist in combination with either another therapeutic agentor an addictive agent, as described infra.

In particular embodiments, the composition comprising a PPARγ agonistand another therapeutic agent is administered in one or more doses of atablet formulation, typically for oral administration. The tabletformulation may be, e.g., an immediate release formulation, a controlledrelease formulation, or an extended release formulation, e.g., a depotformulation. In particular embodiments, extended release formulations ofthe invention release at least 80% of the active ingredients in vivoover a period of greater than 24 hours, greater than 48 hours, greaterthan one week, greater than one month, or even greater than 2 or 4months. Extended release formulations of the invention therefore allowfor less frequency of dosing to the mammal in need thereof than othermore immediate or controlled release formulations.

In one embodiment, a tablet formulation comprises an effective amount ofa composition comprising a PPARγ agonist and another therapeutic agent.In particular embodiments, a tablet comprises about 1, 5, 10, 20, 30, 50100, 150, 200, 250, or 300 mg of a PPARγ agonist, such as pioglitazone,and about 1, 5, 10, 20, 30, 50 100, 150, 200, 250, or 300 mg of anothertherapeutic agent.

The present invention further includes unit dosage forms ofpharmaceutical compositions comprising a PPARγ agonist and anothertherapeutic agent. Each unit dosage form comprises a therapeuticallyeffective amount of a pharmaceutical composition of the presentinvention, when used in the recommended amount. For example, a unitdosage form may include a therapeutically effective amount in a singletablet, or a unit dosage form may include a therapeutically effectiveamount in two or more tablets, such that the prescribed amount comprisesa therapeutically effective amount.

As noted above, the present invention includes compositions (includingdelivery vehicles) comprising both nicotine and a PPARγ agonist, such aspioglitazone. In particular embodiments, the invention includes atransdermal patch suitable for drug delivery, which patch comprises bothnicotine and a PPARγ agonist, such as pioglitazone. In particularembodiments, the patch provides for continued or controlled release ofboth nicotine and the PPARγ agonist. In one embodiment, the transdermalpatch provides for 16 or 24 hour release of nicotine and the PPARγagonist, e.g., pioglitazone. In one embodiment, the dosage ofpioglitazone released over 16 to 24 hours is between 5-45 mg, between5-15 mg, between 10-15 mg, or about 5, about 10, or about 15 mg. Incertain embodiments, the dosage of pioglitazone released over the 16-24hours is less than or equal to 15 mg or less than or equal to 10 mg. Inparticular embodiments, it is about 15 mg per 16 or 24 hours. In certainembodiments, the dosage of nicotine released over 16-24 hours is between5 and 25 mg, e.g., about 21 mg, 14 mg or 7 mg.

A number of the PPARγ agonists and other therapeutic agents describedherein are approved for human use at particular dosages. The presentinvention contemplates using these agents at their approved dosages orat other effective dosages. Since the combination of a PPARγ agonist andanother therapeutic agent has been demonstrated to have synergisticefficacy, it is understood that effective amounts of one or both agentsmay be reduced when provided together, as compare to the effectiveamount of each when provided alone. In particular embodiments, a PPARγagonist is provided to a subject in an amount in the range of 0.1-1000mg/day, 1-1000 mg/day, 10-100 mg/day, or 25-50 mg/day. In oneembodiment, pioglitazone is provided to a patient at about 30 mg/day.

Table 1 lists representative agents used in the present invention andprovides the daily dosages at which these agents are conventionallyadministered to adults for other indications, which dosages are believedto be useful for administration in accordance with the methods of thepresent invention in the treatment or prevention of addiction andrelapse use or practice. Dosages listed are oral unless otherwiseindicated. It is believed that the dosages of these agents may bereduced when delivered in combinations of a PPARγ agonist and anadditional therapeutic agent in accordance with the present inventionfor the treatment or prevention of addiction or for the treatment orprevention of relapse use. These reductions may be up to 10% ofconventional dosages, or up to 20% of conventional dosages, or up to onethird of conventional dosages, up to one half of conventional dosages orup to two thirds of conventional dosages. For example, pioglitazone ismost commonly dosed at 30 mg per day for treatment of diabetes, whichdosage was found to be effective for the treatment of alcoholism(Example 22). When combined with 50 mg/day naltrexone in accordance withthe present invention for treatment of addiction, it is believedtherapeutic effect may be seen at 10-15 mg per day of pioglitazone.

TABLE 1 Therapeutic Agent Exemplary Dosage Applied as Single AgentPioglitazone 15-45 mg Rosiglitazone 2-8 mg Troglitazone 200-600 mgRimonabant 10-20 mg Buprenorphine 0.3 mg (IV or IM) 12-16 mg(sublingual) Naltrexone 25-50 mg Fluoxetine 20-80 mg Mirtazipine 15-45mg Topiramate 400 mg Levetiracetam 1,000-6,000 mg Gabapentin 900-1,800mg Ondansetron 8-24 mg Bupropion 200-400 mg Butorphanol 0.5-4 mg (IM orIV), 1-2 mg (nasal spray) Codeine 30-240 mg Dextropopoxyphene 65-240 mgDiamorphine 5-60 mg Morphine 15-200 mg Fentanyl 2.0-100 μg/kg or0.15-7.5 mg (IM or IV), 12.5-100 μg/hr (transdermal patch), 0.2-1.6 mg(oral lozenge), 0.1-1.6 mg (buccal tablets) Oxycodone 5-10 mgHydrocodone 5-100 mg Hydromorphone 2-25 mg Levorphanol 2-3 mgMeptazocine 75-600 mg Meperidine 13-200 mg Methadone 10-120 mg

In one embodiment, a unit dosage form of a pharmaceutical composition ofthe present invention comprises about 15-45 mg of pioglitazone and about25-50 mg of naltrexone. This unit dosage form may consist of one or moretablets. In one particular embodiment, a unit dosage form of apharmaceutical composition of the present invention comprises about 30mg of pioglitazone and about 50 mg of naltrexone. This unit dosage formmay consist of one or more tablets.

In one embodiment, a unit dosage form of a pharmaceutical composition ofthe present invention comprises about 15-45 mg of pioglitazone and about5-10 mg of oxycodone. In another embodiment, a unit dosage form of apharmaceutical composition of the present invention comprises about15-45 mg of pioglitazone and about 5-100 mg of hydrocodone. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 15-45 mg of pioglitazone and about0.5-4.0 mg (IM or IV) or about 1.0-2.0 mg (nasal spray) of butorphanol.In another embodiment, a unit dosage form of a pharmaceuticalcomposition of the present invention comprises about 15-45 mg ofpioglitazone and about about 30-240 mg of codeine. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 15-45 mg of pioglitazone and about65-240 mg of dextropopoxyphene. In another embodiment, a unit dosageform of a pharmaceutical composition of the present invention comprisesabout 15-45 mg of pioglitazone and about 5-60 mg of diamorphine. Inanother embodiment, a unit dosage form of a pharmaceutical compositionof the present invention comprises about 15-45 mg of pioglitazone andabout 15-200 mg of morphine. In another embodiment, a unit dosage formof a pharmaceutical composition of the present invention comprises about15-45 mg of pioglitazone and about 0.3 mg of fentanyl, which may be inthe form of a transmucosal lozenge. In another embodiment, a unit dosageform of a pharmaceutical composition of the present invention comprisesabout 15-45 mg of pioglitazone and about 2-25 mg of hydromorphone. Inanother embodiment, a unit dosage form of a pharmaceutical compositionof the present invention comprises about 15-45 mg of pioglitazone andabout 2.0 mg of levorphanol. In another embodiment, a unit dosage formof a pharmaceutical composition of the present invention comprises about15-45 mg of pioglitazone and about 75-600 mg of meptazocine. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 15-45 mg of pioglitazone and about13-200 of meperidine. In another embodiment, a unit dosage form of apharmaceutical composition of the present invention comprises about15-45 mg of pioglitazone and about 10-120 mg of methadone.

In one embodiment, a unit dosage form of a pharmaceutical composition ofthe present invention comprises about 2-8 mg of rosiglitazone and about5-10 mg of oxycodone. In another embodiment, a unit dosage form of apharmaceutical composition of the present invention comprises about 2-8mg of rosiglitazone and about 5-100 mg of hydrocodone. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 2-8 mg of rosiglitazone and about0.5-4.0 mg (IM or IV) or about 1.0-2.0 mg (nasal spray) of butorphanol.In another embodiment, a unit dosage form of a pharmaceuticalcomposition of the present invention comprises about 2-8 mg ofrosiglitazone and about about 30-240 mg of codeine. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 2-8 mg of rosiglitazone and about65-240 mg of dextropopoxyphene. In another embodiment, a unit dosageform of a pharmaceutical composition of the present invention comprisesabout 2-8 mg of rosiglitazone and about 5-60 mg of diamorphine. Inanother embodiment, a unit dosage form of a pharmaceutical compositionof the present invention comprises about 2-8 mg of rosiglitazone andabout 15-200 mg of morphine. In another embodiment, a unit dosage formof a pharmaceutical composition of the present invention comprises about2-8 mg of rosiglitazone and about 0.3 mg of fentanyl. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 2-8 mg of rosiglitazone and about 2-25mg of hydromorphone. In another embodiment, a unit dosage form of apharmaceutical composition of the present invention comprises about 2-8mg of rosiglitazone and about 2.0 mg of levorphanol. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 2-8 mg of rosiglitazone and about75-600 mg of meptazocine. In another embodiment, a unit dosage form of apharmaceutical composition of the present invention comprises about 2-8mg of rosiglitazone and about 13-200 of meperidine. In anotherembodiment, a unit dosage form of a pharmaceutical composition of thepresent invention comprises about 2-8 mg of rosiglitazone and about10-120 mg of methadone.

The various unit dosage forms described above comprising both a PPARγagonist and an opioid agonist may be altered to replace pioglitazone orrosiglitzeon with another PPARγ agonist at an acceptable dosage, suchas, e.g., troglitazone at about 200-600 mg.

Certain combinations of PPARγ agonists and other therapeutic agents maynot be readily adaptable to coformulation. For example, one of theagents may be more amenable to intravenous administration, while anotherof the agents may be more amenable to oral administration. Or, the serumhalf life of the two agents may be such that one must be administeredmore frequently than the other. Accordingly, the present inventioncontemplates kits comprising one or more unit dosage forms of a PPARγagonist and one or more unit dosage forms of another therapeutic agent,such that the two unit dosage forms may be provided to a subject in atherapeutically effective manner. In particular embodiments, a kitcomprises unit dosage forms of pioglitazone and naltrexone; ciglitazoneand naltrexone; rosiglitazone and naltrexone; englitazone andnaltrexone; rivoglitazone and naltrexone; darglidazone and naltrexone;pioglitazone and fluoxentine; ciglitazone and fluoxentine; rosiglitazoneand fluoxentine; englitazone and fluoxentine; rivoglitazone andfluoxentine; darglidazone and fluoxentine; pioglitazone and mirtazapine;ciglitazone and mirtazapine; rosiglitazone and mirtazapine; englitazoneand mirtazapine; rivoglitazone and mirtazapine; darglidazone andmirtazapine; pioglitazone and topiramate; ciglitazone and topiramate;rosiglitazone and topiramate; englitazone and topiramate; rivoglitazoneand topiramate; darglidazone and topiramate; pioglitazone andlevetiracetam; ciglitazone and levetiracetam; rosiglitazone andlevetiracetam; englitazone and levetiracetam; rivoglitazone andlevetiracetam; darglidazone and levetiracetam; pioglitazone andgabapentin; ciglitazone and gabapentin; rosiglitazone and gabapentin;englitazone and gabapentin; rivoglitazone and gabapentin; darglidazoneand gabapentin; piolitazone and ondansetron; ciglitazone andondansetron; rosiglitazone and ondansetron; englitazone and ondansetron;rivoglitazone and ondansetron; darglidazone and ondansetron;pioglitazone and antalarmin; ciglitazone and antalarmin; rosiglitazoneand antalarmin; englitazone and antalarmin; rivoglitazone andantalarmin; darglidazone and antalarmin.

In one embodiment, the present invention includes a kit comprising unitdosage forms of a PPARγ agonist and unit dosage forms of nicotine. Inone embodiment, the unit dosage forms of nicotine comprise a pluralityof different unit dosage forms of nicotine, wherein the different dosageforms of nicotine represent decreasing amount that may be taken oneafter the other over a period of time, so as to overcome addiction andeffectuate withdrawal from the nicotine. In particular embodiments, thePPARγ agonist is pioglitazone. The unit dosage forms of nicotine may bepresent, e.g., in the form of a transdermal or skin patch, gum, or alozenge.

EXAMPLES

The following examples describe a number of studies performed todemonstrate the effect of various PPARγ agonists for treating addictionand preventing relapse for a variety of addictive agents. Certainexamples describe studies demonstrating the effect of PPARγ agonistsused in combination with other therapeutic agents to treat alcoholaddiction. These studies were performed using well-validated laboratoryanimal models for alcohol abuse and cocaine abuse.

Most of the studies described in Examples 1-21 were conducted usingmale, genetically selected alcohol-preferring rats, referred to asMarchigian Sardinian alcohol-preferring (msP) rats. These animals werebred at the Department of Pharmacological Sciences and ExperimentalMedicine of the University of Camerino (Marche, Italy) for 60generations from Sardinian alcohol-preferring rats of the 13^(th)generation, provided by the Department of Neurosciences of theUniversity of Cagliari, Italy. At the time of the experiments, theirbody weight ranged between 300 and 350 g. They were housed in a room ona reverse 12-hourlight/dark cycle (lights off at 9:00 a.m.), temperatureof 20-22° C. and humidity of 45-55%. The rats were offered free accessto tap water and food pellets (4RF18, Mucedola, Settimo Milanese,Italy). In the operant self-administration experiments, maleheterogeneous Wistar rats (Charles River, Germany) were used.

Experiments were performed at 9:30 a.m., which is the beginning of thedark phase of the light/dark cycle. Separate groups of animals were usedin each experiment. All procedures were conducted in adherence to theEuropean Community Council Directive for Care and Use of LaboratoryAnimals and the National Institutes of Health Guide for the Care and Useof Laboratory Animals.

Pioglitazone, rosiglitazone, fluoxetine, mirtazapine, topiramate,gabapentine, ondansetrone, and levetiracetam was purchased fromcommercial sources. Yohimbine and ciglitazone were purchased from SIGMASRL (Mi, Italy). Naltrexone and GW9662 were obtained from TOCRIS (U.K).

Prior to administration, pioglitazone was suspended in distilled water,and the resulting suspension was maintained under constant agitationuntil administration. The drug was given orally (OS) via gavageprocedure in a volume of 1.0 ml/kg. Yohimbine was dissolved in distilledwater and was administered intraperitoneally (IP) in a volume of 1.0ml/kg. Naltrexone hydrochloride was dissolved in distilled water andadministered IP in a volume of 1.0 ml/kg. Rosiglitazone, fluoxetine,mirtazapine, topiramate, gabapentin and levetiracetam were suspended indistilled water, and resulting suspensions were maintained underconstant agitation until administration. These drugs were given orally(OS) via gavage procedure in a volume of 1.0 ml/kg. Yohimbina wasdissolved in distilled water and was administered intraperitoneally (IP)in a volume of 1.0 ml/kg. GW9662 was prepared in 5% DMSO and 5% TWIN 80and was given either IP (1 ml/kg) or intacerebroventricularly (ICV, 1μl/rat). Antalarmin was prepared in 10% TWIN 80 and was given IP (1ml/kg). Ondansetron was prepared in aqueous solution and was given IP (1ml/kg).

At the beginning of the experiments, msP rats were allowed free choicebetween water and 10% (v/v) alcohol 24 h/day for at least 15 days. Thefluids were offered in graduated drinking tubes equipped with metallicdrinking spouts. The position (to the right or left) of alcohol andwater drinking tubes was changed daily to avoid the development of sidepreference. Water and food were available ad libitum, while alcoholaccess was either restricted to 2 hours/day (Examples 1 and 2) or wasavailable 24 hours/day (Examples 3 and 4). Alcohol, water and foodintakes were measured.

Training and testing were conducted in standard operant chambers (MedAssociate) located in sound-attenuating, ventilated environmentalcubicles. Each chamber was equipped with a drinking reservoir (volumecapacity: 0.30 ml) positioned 4 cm above the grid floor in the centre ofthe front panel of the chamber, and two retractable levers located 3 cmto the right or to the left of the drinking receptacle. Auditory andvisual stimuli were presented via a speaker and a light located on thefront panel. A microcomputer controlled the delivery of fluids,presentation of auditory and visual stimuli, and recording of thebehavioural data.

Rats were trained to self-administer 10% alcohol (v/v) in 30-min. dailysessions on a fixed-ratio 1 schedule of reinforcement, in which eachresponse resulted in delivery of 0.1 ml of fluid as previously described(Economidou et al. 2006). For the first 3 days, rats were allowed tolever-press for a 0.2% (w/v) saccharin solution, and then trained toself-administer 10% alcohol by fading the saccharine (Weiss et al.1993). During the first 6 days of training, rats were allowed tolever-press for a 5.0% (v/v) alcohol solution containing 0.2% (w/v)saccharin. Starting on day 7, the concentration of alcohol was graduallyincreased from 5.0% to 8.0% and finally to 10.0% (w/v), while theconcentration of saccharin was correspondingly decreased to 0%.

Cue-induced reinstatement of alcohol-seeking behaviour experimentalprocedures consisted of three phases: (1) conditioning phase; (2)extinction phase; and (3) reinstatement phase, as described below.

For the conditioning phase, at the completion of the fading procedure(see above), in 30 min daily sessions, animals were trained todiscriminate between 10% alcohol and water. Beginning withself-administration training at the 10% alcohol concentration,discriminative stimuli (SD) predictive of alcohol versus wateravailability were presented during the alcohol and waterself-administration sessions, respectively. The discriminative stimulusfor alcohol consisted of the odour of an orange extract (S⁺) whereaswater availability (i.e. no reward) was signalled by an anise extract(S⁻). The olfactory stimuli were generated by depositing six to eightdrops of the respective extract into the bedding of the operant chamber.In addition, each lever-press resulting in delivery of alcohol waspaired with illumination of the chamber's house light for 5 sec (CS⁺).The corresponding cue during water sessions was a 5 second tone (70 dB)(CS⁻). Concurrently with the presentation of these stimuli, a 5 sec.time-out period was in effect, during which responses were recorded butnot reinforced. The olfactory stimuli serving as S⁺ or S⁻ for alcoholavailability were introduced one minute before extension of the leversand remained present throughout the 30-min. sessions. The bedding of thechamber was changed and bedding trays were cleaned between sessions.During the first three days of the conditioning phase, the rats weregiven alcohol sessions only. Subsequently, alcohol and water sessionswere conducted in random order across training days, with the constraintthat all rats received a total of 10 alcohol and 10 water sessions.

For the extinction phase, after the last conditioning day, rats weresubjected to 30-min extinction sessions for 15 consecutive days. Duringthis phase, sessions began by extension of the levers withoutpresentation of the SD. Responses at the lever activated the deliverymechanism but did not result in the delivery of liquids or thepresentation of the response-contingent cues (house light or tone).

The reinstatement testing phase began the day after the last extinctionsession. This test lasted 30-min under conditions identical to thoseduring the conditioning phase, except that alcohol and water were notmade available. Sessions were initiated by the extension of both leversand presentation of either the alcohol S⁺ or water S⁻ paired stimuli.The respective SD remained present during the entire session andresponses at the previously active lever were followed by activation ofdelivery mechanism and a 5-sec presentation of CS⁺ in the S⁺ conditionor the CS⁻ (tone) in the S⁻ condition. Rats were tested under the S⁻/CS⁻condition on day 1 and under S⁺/CS⁺ condition on day 2.

Stress-induced reinstatement of alcohol-seeking experimental proceduresconsisted of three phases: (1) training phase; (2) extinction phase; and(3) reinstatement phase, as described below.

For the training phase, after completion of the fading procedure, msPrats were trained to self-administer 10% (v/v) alcohol for 15 days in30-min daily sessions under a FR1 schedule of reinforcement. During theinfusion, a stimulus house light was turned on for 5 s (time out; TO).Lever presses during the TO period were counted, but did not lead tofurther infusions.

For the extinction phase, after the last alcohol self-administrationsession, animals were subjected to 30-min extinction sessions for 15consecutive days. Responses at the lever activated the deliverymechanism but did not result in the delivery of alcohol.

For the reinstatement phase, the day after the last extinction session,rats were injected with yohimbine (1.25 mg/kg) and after 30 minutes wereplaced in the operant chamber and lever presses was monitored for 30min. It is known that administration of the α-2 adrenoreceptorantagonist yohimbine, increasing brain noradrenaline cell firing andrelease, acts as a pharmacological stressor and facilitates relapse toalcohol seeking (Le et al. 2005).

Analysis of variance (ANOVA) of data was used to evaluate the results.When appropriate, ANOVA was followed by post-hoc tests. In particular,the effect of acute administration of pioglitazone, naltrexone or theircombination on alcohol intake (Examples 1 and 2) was evaluated by meanof a two-way ANOVA with two within factors (time and treatment). Theeffect of chronic administration of pioglitazone, naltrexone or theircombination on alcohol intake (Examples 3 and 4) was evaluated by meanof a three-way ANOVA with one between factor (treatment) and two betweenfactors (days and hours). The effect of pioglitazone on reinstatement ofalcohol seeking (Examples 5 and 6) was evaluated by mean of a one-wayANOVA with repeated measures using drug dose as a within subject factor.Alcohol self-administration (Example 7) in Wistar rats was studied byone-way ANOVA with one within factor (dose). Post hoc analysis wascarried out using the Newman-Keuls test.

Example 1 Effect of Acute Pioglitazone Administration on VoluntaryEthanol Intake

The effect of acute pioglitazone administration on voluntary ethanolintake was demonstrated by first training rats to drink 10% (w/v)alcohol for 24 hours a day (free choice between water and ethanol).After acquisition of a stable baseline of ethanol intake (6-8 g/kg bw;daily), alcohol access was restricted to 2 hours a day at the beginningof the dark phase. Water and food were freely available.

Once stable ethanol drinking baseline was reached (also under limitedaccess conditions), rats (n=7) were tested for the effect ofpioglitazone (0.0, 10.0, 30.0 mg/kg) using a within subjectcounterbalanced Latine square design where each animal received all drugdoses. Before starting the treatment, rats were trained to gavageadministration procedures for three days, during which they receivedvehicle (distilled water).

Treatments were carried out at intervals of at least three days. Beforeeach ethanol drinking experiment, msP rats received two doses ofpioglitazone or vehicle at 12 hours and at 1 hour before access toethanol. Drinking experiments were conducted right at the beginning ofthe dark cycle. Alcohol, water and food intakes were monitored at 30,60, 90 and 120 minutes after ethanol was made available.

Analysis of variance revealed the absence of a significant treatmenteffect on ethanol intake F(2,6)=1.22 NS]. However, a significanttreatment time interaction was detected [F(6,18)=6.87 p<0.01]. As shownin FIG. 1, post-hoc tests revealed that acute treatment with 30 mg/kg ofpioglitazone significantly reduced ethanol consumption at 2 hours butnot at 30, 60, or 90 minutes. The selectivity effect was demonstrated bythe lack of significant effects on water and food consumption (data notshown).

Example 2 Effect of Acute Pioglitazone Plus Naltrexone Administration onVoluntary Ethanol Intake

In this experiment, the effect of the co-administration of pioglitazoneand naltrexone on alcohol consumption was examined to demonstrate thatPPARγ agonists could enhance the inhibitory action of opioid antagonistson ethanol intake. The dose of naltrexone used in these studies (0.25mg/kg) was previously shown to be marginally effective in reducingethanol intake in msP rats under the same experimental conditions(Ciccocioppo et al. 2007).

The msP rats (n=8) were prepared for the study as described inExample 1. After acquisition of a stable baseline of ethanol intake,alcohol access was restricted to 2 hours a day at the beginning of thedark phase. Water and food were freely available. Animals were testedfor the effect of the combination between pioglitazone (0.0, 10.0, 30.0mg/kg) given at 12 hours and at 1 hour before access to ethanol andnaltrexone (0.0 and 0.25 mg/kg) injected 2 minutes after the secondpioglitazone administration. The experiment was conducted using a withinsubject counterbalanced Latine square design where each animal receivedall drug doses.

These experiments were conducted at the beginning of the dark cycle andalcohol, and water and food intakes were monitored at 30, 60, 90 and 120minutes after ethanol was made available. Water and food intakes werenot significantly modified by the various treatments.

Analysis of variance revealed a significant overall effect of treatment[F(3,7)=5.95 p<0.01] on alcohol intake. As shown in FIG. 2, post-hoctests demonstrated that both naltrexone alone andnaltrexone+piolgitazone significantly reduced ethanol intake at 30, 60,and 90 minutes. At 120 minutes, the treatments with naltrexone alone andnaltrexone+pioglitazone (10 mg/kg) did not show significant effects. Incontrast, compared to controls, the co-administration ofnaltrexone+pioglitazone (30 mg/kg) showed a significant effect also at120 minutes (p<0.05). This data suggests that co-administration of thetwo drugs results in an enhancement of their effects, or could result inan increased duration of naltrexone effect.

Example 3 Effect of Subchronic Pioglitazone Administration on VoluntaryEthanol Intake

The effect of subchronic pioglitazone administration was demonstratedusing rats trained to drink 10% (v/v) alcohol for 24 hours a day (freechoice between water and ethanol) until a stable baseline of ethanolintake was reached. At this point, msP rats (N=9/group) were tested forthe effect of pioglitazone (0.0, 10.0, or 30.0 mg/kg) on ethanol intakeusing a between subject design, in which each group of animals receiveda different dose of drug. Before starting the treatment, rats weretrained to gavage administration procedures for three days, during whichthey received vehicle (distilled water).

Pioglitazone treatment was continued for seven consecutive days, anddrug (or vehicle) was administered twice a day at 12 hour and at 1 hourbefore the beginning of dark period of the light/dark cycle. Alcohol,water and food intakes were monitored at 2, 8 and 24 hours. Fluids andfood intakes were monitored for three additional days after the end ofthe drug treatment period.

Sub-chronic (7 days) pioglitazone administration significantly reducedvoluntary ethanol intake in msP rats. Analysis of variance revealed asignificant overall effect of treatment [F (2,33)=9.51; p<0.01]. Asshown by post-hoc tests, the effect appeared from the first day oftreatment at the highest drug dose (FIGS. 3A, 3B and 3C). The effectprogressively increased during treatment, and starting from the 4^(th)day of treatment, both drug doses (10 and 30 mg/kg) significantlyreduced ethanol intake.

During treatment, water consumption was rather low and was notsignificantly affected by drug treatment. Conversely, food intake (FIG.3D) was significantly increased by pioglitazone [F (2,33)=7.34 p<0.01].The effect was higher after administration of the lowest dose (10 mg/kg)of drug. At the end of the treatment, rats gradually recovered from theeffect of the drug and ethanol intake and progressively returned atpre-treatment levels (data not shown).

Example 4 Effect of Chronic Pioglitazone Plus Naltrexone Administrationon Voluntary Ethanol Intake

The effect of chronic co-administration of pioglitazone and naltrexoneon alcohol consumption was studied to evaluate if PPARγ agonists couldalso enhance the inhibitory action of opioid antagonists on ethanolintake after repeated treatments. As in the studies described in Example2, a naltrexone dose (0.25 mg/kg) previously shown to be marginallyeffective in reducing ethanol intake in msP rats was used (Ciccocioppoet al. 2007). According to a between-subject design, four groups of msPrats (N=9/group) were prepared as described in Example 3. Specifically,once a stable baseline of daily ethanol consumption was reached,different groups of msP rats were tested for the effect of pioglitazonein combination with naltrexone. For seven consecutive days, msP ratsreceived pioglitazone treatments (0.0, 10.0, or 30.0 mg/kg) at 12 hourand at 1 hour before the beginning of the dark of the light/dark cycle,while naltrexone (0.0 and 0.25 mg/kg) was injected 2 minutes after thesecond pioglitazone administration. Alcohol, water and food intakes weremonitored at 2, 8 and 24 hours. Fluids and food intakes were monitoredfor three additional days after the end of the drug treatment period.

Sub-chronic (7 days) administration of naltrexone ornaltrexone+pioglitazone significantly reduced voluntary ethanol intakein msP rats. Analysis of variance revealed a significant overall effectof treatment [F(3,32)=9.59 p<0.01]. As shown by post-hoc tests (FIGS.4A, 4B and 4C), naltrexone significantly reduced ethanol intake at 2hours (p<0.05) but not at 8 and 24 hours. In addition, the effectprogressively decayed during treatment days. Animals treated withpioglitazone plus naltrexone, instead, significantly reduced theirdrinking at all time points tested (2, 8 and 24 hours). This effectremained significant for the entire period of treatment. These resultsindicate that pioglitazone and naltrexone co-administration may resultin additive or synergistic effects on ethanol consumption.

During treatment, water consumption was rather low and was notsignificantly affected by drug treatment. Conversely, food intake wassignificantly increased by pioglitazone [F(3,32)=5.34 p<0.05] (FIG. 4D).The effect was higher after administration of the lowest dose (10 mg/kg)of drug. Post hoc comparisons showed that on the first day naltrexonealone significantly reduced food consumption. Conversely, thecombination of pioglitazone plus naltrexone resulted in an increase offood intake toward vehicle treated controls (data not shown). At the endof the treatment, rats gradually recovered from the effect of the drugand ethanol intake progressively returned at pre-treatment levels.

Example 5 Effect of Acute Pioglitazone Administration onYohimbine-Induced Reinstatement of Alcohol Seeking

Stress and anxiety are major factors in resuming alcohol use in formerabstinent alcoholics. Yohimbine, an α-2 adrenoreceptor antagonist thatincreases brain noradrenaline cell firing (Aghajanian and VanderMaelen1982) and release (Abercrombie, Keller et al. 1988), and acts as apharmacological stressor (Holmberg, Gershon et al. 1962; Le, Harding etal. 2000; Lee, Tiefenbacher et al. 2004), is known to increase alcoholcraving in humans and to resume extinguished alcohol seeking in rats.This pharmacological stressor was used to investigate the effect ofpioglitazone or of naltrexone on the reinstatement of drug seeking inrats previously trained to alcohol self-administration.

To demonstrate the effect of TZDs on stress-induced relapse to alcoholseeking, following acquisition of a stable baseline of 10% ethanol,responding msP rats (n=10) were subjected to an extinction period (14days) during which ethanol responding progressively decreased. The dayafter the last extinction session, rats were subjected to thereinstatement test. The animals were treated OS with pioglitazone (0.0,10.0, or 30.0 mg/kg) at 12 hours and 1 hour before the reinstatementtest. Yohimbine (1.25 mg/kg, IP) was given 30 min after the lastpioglitazone administration.

Animals received all drug treatments according to a counterbalance Latinsquare design. A 3-day interval, during which animals were subjected toextinction sessions, was allowed between drug tests. In thereinstatement test, active and inactive lever responses were recorded.

A stable baseline of responding for 10% (v/v) alcohol was established in15 days. Following this alcohol self-administration phase, extinctiontraining began. During the extinction phase, responding progressivelydecreased, and the last extinction day values were 16.1±3.9. Theintraperitoneal administration of the alpha-2 adrenoceptor antagonistyohimbine at the dose of 1.25 mg/kg significantly reinstated the operantresponse for alcohol F(1,18)=22.78 p<0.01]. As shown by the analysis ofvariance, pre-treatment with pioglitazone significantly reduced theeffect of yohimbine [F(2,9)=12.21, p<0.01] (FIG. 5). Post-hoc analysisdemonstrated a significant inhibition of reinstatement followingadministration of 30 mg/kg of pioglitazone (p<0.01).

At the lowest dose (10 mg/kg), pioglitazone showed a clear trend(p=0.07) to an inhibition of yohimbine effect. Analysis of inactivelever responding revealed absence of treatment effects at this lever.This indicated the selectivity of the effect of yohimbine in elicitingreinstatement of alcohol seeking.

Example 6 Effect of Acute Pioglitazone Administration on Cue-InducedReinstatement of Alcohol Seeking

Like stress, environmental condition factors have been shown to havesignificant role in eliciting alcohol craving in abstinent individuals.Here, using a well validated animal model of cue-induced relapse theeffect of pioglitazone on conditioned reinstatement of alcohol seekingwas investigated.

msP rats (n=14) were trained to operantly self-administer 10% ethanol orwater in 30 min daily session on an FR-1 schedule of reinforcement,where each response resulted in delivery of 0.1 ml of fluid. Ethanolavailability was signalled by the odor of an orange extract, whichserved as a discriminative stimulus. In addition, each lever pressresulting in delivery of ethanol was paired with illumination of thehouse light for 5 s (S⁺/CS⁺). For water, anise odor and a 5 sec whitenoise were employed as discriminative and contiguous cues (S⁻/CS⁻),respectively. Rats were than subjected to daily extinction sessions,during which lever presses progressively decreased.

The reinstatement test was conducted by re-exposing them to theconditioned stimuli predictive of ethanol or water availability but inthe absence of the fluids. Pioglitazone (0.0, 10.0, 30.0 mg/kg) wasgiven 12 hours and 1 hour before the reinstatement test. Experimentswere conducted at the beginning of the dark phase of the light/darkcycle. Animals received all drug treatments according to acounterbalance Latin square design, and a 3-day interval was allowedbetween reinstatement sessions. In the reinstatement test, active andinactive lever responses were recorded.

Throughout the conditioning phase, in which animals discriminatedbetween alcohol or water availability, rats responded at a higher levelfor alcohol. ANOVA showed a significant overall effect of conditioning[F(1.28)=41.89, p<0.01]. On the last day of the discrimination period,animals reached a lever pressing response of about 60 in 30 min., whilethe response for water was 20. During extinction, lever pressingprogressively decreased to 5.87±1.07 of the last extinction day. In thereinstatement test, the ANOVA showed that cues had a significant overalleffect on alcohol-seeking [F(1.28)=30.4, p<0.01]. A more detailedanalysis showed a robust reinstatement of responding under the S⁺/CS⁺(p<0.01) but not under the S⁻/CS⁻ compared with the last day ofextinction. As shown in FIG. 6, conditioned reinstatement ofalcohol-seeking was not significantly modified by pre-treatment withpioglitazone. Responses at the inactive lever were not influenced by thetreatment (data not shown).

Example 7 Effect of Ciglitazone Administration on EthanolSelf-Administration in Wistra Rats

This study was performed to demonstrate the the effect of pioglitazoneon ethanol intake extends also to other PPARγ agonists. The effect ofciglitazone, a structurally different TDZ, onethanol-self-administration was determined. In addition, to verify thatthe effect observed with pioglitazone extends to other experimentalalcohol intake models, these studies were performed in heterogeneousWistar rats under operant self-administration conditions.

Wistra rats (n=7) were trained to self-administer ethanol 30 min/dayunder FR1 schedule of reinforcement. Once a stable level of respondingwas reached, in a within subject counterbalance order (Latin squaredesign), rats were treated with ciglitazone (0.0, 5.0 or 20.0 mg/kg)given IP 30 minutes before the beginning of the self-administrationsession. The number of responses to the active and inactive levers wererecorded. A 3-day interval was allowed between self-administrationsessions.

During ethanol self-administration, Wistar rats acquired robust operantalcohol responding. At the end of this phase, rats pressed the alcohollever an average of 30-35 times in 30-min. At this point, animals weretreated with ciglitazone IP. Results showed that ciclitazone treatmentsignificantly reduced ethanol self-administration [F(2,6)=5.87 p<0.05].Responding at the inactive lever was very low and was not affected bydrug treatment [F(2,6)=1.52 NS]. Post hoc tests showed that ethanolself-administration was significantly reduced following administrationof the highest dose of drug (FIG. 7).

Example 8 Effect of Acute Rosiglitazone Administration on VoluntaryEthanol Intake

The ability of another TZD, rosiglitazone, to reduce ethanol intake wasdemonstrated. MsP rats were first trained to drink 10% (w/v) alcohol for24 hours a day (free choice between water and ethanol). Once stableethanol drinking baseline was reached (6-8 g/kg/day), rats (n=28) weretested for the effect of rosiglitazone (0.0, 7.5 and 15 mg/kg) using abetween subject design. Before starting the treatment, rats were trainedto gavage administration procedures for three days, during which theyreceived vehicle (distilled water). Rosiglitazone was given twice, at 12hours and 1 hour before access to ethanol. Drinking experiments startedat the beginning of the dark cycle. Alcohol, water and food intakes weremonitored at 2, 8 and 24 hours after ethanol was made available.

Analysis of variance revealed a significant treatment effect on ethanolintake [F(2,18)=0.4 p<0.05]. As shown in FIG. 8, post-hoc Newman-Keulstests revealed that acute treatment with 15 mg/kg of rosiglitazonesignificantly reduced ethanol consumption at 2 hours (p<0.05).Inhibition of ethanol drinking was highly significant at 24 hours(p<0.01). The selectivity effect was demonstrated by the lack ofsignificant effects on water and food consumption (data not shown).Follow-up studies showed that treatment with 5 or 15 mg/kg ofrosiglitazone increased food consumption at 24 hours [F(2,25)=13.11p<0.01].

Example 9 Effect of IP Administration of the PPARγ Antagonist GW9662 onPioglitazone-Induced Reduction of Ethanol Intake

This experiment demonstrated that the effect of pioglitazone on ethanolintake was mediated by activation of PPARγ receptors. After acquisitionof a stable baseline of ethanol intake, msP rats (n=22) were tested forthe effect of GW9662 on pioglitazone-induced reduction of ethanolintake. Rats were treated with 30 mg/kg of pioglitazone given OS 1 hourbefore access to ethanol. GW9662 was administered IP 30 min afterpioglitazone administration, and additional 30 min were awaited beforegiving ethanol access to rats. Before starting the treatment, rats weretrained to gavage and IP administration procedures for three days.Experiment was conducted in a between subject design (n=22). Anothergroup of msP rats (n=22) received GW9662 alone to demonstrate the effectof PPARγ blockade on ethanol consumption. Drinking experiments startedat the beginning of the dark cycle. Alcohol, water and food intakes weremonitored at 2, 8 and 24 hours after ethanol was made available.

As shown in FIG. 9A, analysis of variance revealed that blockade ofPPARγ receptors by GW9662 did not modify ethanol drinking in msP rats[F(2,18)=0.40 NS]. However, analysis of variance revealed a significanttreatment effect on ethanol intake F(3,24)=18.64 p<0.01] followingadministration of pioglitazone (FIG. 9B). Newman-Keuls tests revealedthat treatment with 30 mg/kg of pioglitazone significantly reducedethanol consumption at 8 and 24 hours (p<0.01). Further experiments alsoshowed that treatment with 30 mg/kg of pioglitazone significantlyreduced ethanol consumption at 2 hours (p<0.05; data not shown).Pretreatment with GW9662 blocked the effect of pioglitazone in a doserelated manner. Water and food consumption were not affected by drugtreatments (data not shown).

Example 10 Effect of ICV Administration of the PPARγ Antagonist GW9662on Pioglitazone-Induced Reduction of Ethanol Intake

This experiment demonstrated that the effect of pioglitazone on ethanolintake is mediated by activation of brain PPARγ receptors. For thispurpose, msP rats (n=6) were treated with GW9662 (5 μg/rat) ICV toselectively block brain PPARγ receptors, while pioglitazone (30 mg/kg)was given OS. The experiment was conduced using a within subjectcounterbalanced Latine square design, where each animal received alldrug doses.

The drinking experiments were conducted at the beginning of the darkcycle, and alcohol, water and food intakes were monitored at 2, 8 and 24hours after ethanol was made available.

Analysis of variance revealed a significant treatment effect on ethanolintake F(3,5)=12.93 p<0.001]. As shown in FIG. 10, post-hoc Newman-Keulstests revealed that treatment with 30 mg/kg of pioglitazonesignificantly reduced ethanol consumption at 2 hours (p<0.05) 8 hours(p<0.05) and at 24 hours (p<0.01). ICV administration of GW9662 did notsignificantly affect ethanol intake per se. However it completelyprevented the effect of pioglitazone. Water and food consumption werenot affected by drug treatments (data not shown).

Example 11 Effect of Acute Naltrexone Administration onYohimbine-Induced Reinstatement of Alcohol Seeking

The inability of naltrexone to reduce yohimbine-induced reinstatement ofalcohol use was demonstrated. Following acquisition of a stable baselineof 10% ethanol, responding msP rats (n=10) were subjected to anextinction period (14 days) during which ethanol respondingprogressively decreased. The day after the last extinction session, ratswere subjected to the reinstatement test.

To determine whether naltrexone was able to prevent the effect of thepharmacological stressor yohimbine, animals (n=7) were treated IP withthe opioid antagonist (0.0, 0.25 and 1.0 mg/kg) 1 hour before thereinstatement test. Yohimbine (1.25 mg/kg, IP) was given 30 min afternaltrexone administration. Animals received all drug treatmentsaccording to a counterbalance Latin square design. A 3-day interval,during which animals were subjected to extinction sessions, was allowedbetween drug tests. In the reinstatement test, active and inactive leverresponses were recorded.

A stable baseline of responding for 10% (v/v) alcohol was established in15 days. Following this alcohol self-administration phase, extinctiontraining began. During the extinction phase, responding progressivelydecreased. The intraperitoneal administration of the alpha-2adrenoceptor antagonist yohimbine at the dose of 1.25 mg/kgsignificantly reinstated the operant response for alcohol F(1,8)=19.99p<0.01]. As shown by the analysis of variance, pre-treatment withnaltrexone did not significantly reduce the effect of yohimbine[F(2,8)=0.46, NS] (FIG. 11). Analysis of inactive lever respondingrevealed absence of treatment effects at this lever (data not shown).This indicates the selectivity of the effect of yohimbine in elicitingreinstatement of alcohol seeking.

Example 12 Effect of Acute Naltrexone Administration on Cue-InducedReinstatement of Alcohol Seeking

The ability of naltrexone to reduce cue-induced reinstatement of alcoholseeking was demonstrated. In this experiment, msP rats (n=9) weretrained to operantly self-administer 10% ethanol or water in 30 mindaily session on an FR-1 schedule of reinforcement, where each responseresulted in delivery of 0.1 ml of fluid. Ethanol availability wassignalled by the odor of an orange extract, which served as adiscriminative stimulus. In addition, each lever press resulting indelivery of ethanol was paired with illumination of the house light for5 s (S⁺/CS⁺). For water, anise odor and a 5 sec white noise wereemployed as discriminative and contiguous cues (S⁻/CS⁻), respectively.Rats were than subjected to a daily extinction sessions during whichlever presses progressively decreased.

Reinstatement tests were conducted by re-exposing them to theconditioned stimuli predictive of ethanol or water availability, but inthe absence of the fluids. Naltrexone (0.0, 0.25 and 1.0 mg/kg) wasgiven one hour before the reinstatement test. Experiments were conductedat the beginning of the dark phase of the light/dark cycle. Animalsreceived all drug treatments according to a counterbalance Latin squaredesign, and a 3-day interval was allowed between reinstatement sessions.In the reinstatement test, active and inactive lever responses wererecorded.

Throughout the conditioning phase, in which animals discriminatedbetween alcohol or water availability, rats responded at a higher levelfor alcohol. During extinction, lever pressing progressively decreased.In the reinstatement test, the ANOVA showed that cues had a significantoverall effect on alcohol-seeking [F(1,8)=36.31, p<0.01]. A moredetailed analysis showed a robust reinstatement of responding under theS⁺/CS⁺ (p<0.01) but not under the S⁻/CS⁻ compared with the last day ofextinction. As shown in FIG. 12, conditioned reinstatement ofalcohol-seeking was significantly reduced by naltrexone [F(2,8)=15.90;p<0.01]. Post-hoc analysis revealed that both doses (0.25 and 1.0 mg/kg)of the opioid antagonist tested significantly reduced reinstatement ofethanol seeking (p<0.01). Responses at the inactive lever were notinfluenced by the treatment (data not shown).

Example 13 Effect of Co-Administration of Pioglitazone and Naltrexone onYohimbine- and Cue-Induced Reinstatement of Alcohol Seeking

The combined effect of a PPARγ agonist, pioglitazone, and an opioidantagonist, naltrexone, on various inducers of reinstated alcoholseeking was determined.

For yohimbine-induced reinstatement of ethanol seeking, afteracquisition of a stable baseline of 10% ethanol responding, msP rats(n=9) were subjected to an extinction period (14 days) during whichethanol responding progressively decreased. The day after the lastextinction session, rats were subjected to the reinstatement test.

To evaluate whether combination of naltrexone plus pioglitazone was ableto prevent the effect of the pharmacological stressor yohimbine, animalswere treated IP with the opioid antagonist (1.0 mg/kg) and OS with theTDZ (30 mg/kg) 1 hour before the reinstatement test. Yohimbine (1.25mg/kg, IP) was given 30 min after naltrexone/pioglitazoneadministration. Animals received all drug treatments according to acounterbalance Latin square design. A 3-day interval, during whichanimals were subjected to extinction sessions, was allowed between drugtests. In the reinstatement test, active and inactive lever responseswere recorded.

For cue-induced reinstatement of alcohol seeking, another group of msPrats (n=10) were trained to operantly self-administer 10% ethanol orwater in 30 min daily session on an FR-1 schedule of reinforcement,where each response resulted in delivery of 0.1 ml of fluid. Ethanolavailability was signalled by the odor of an orange extract, whichserved as a discriminative stimulus. In addition, each lever pressresulting in delivery of ethanol was paired with illumination of thehouse light for 5 s (S⁺/CS⁺). For water, anise odor and a 5 sec whitenoise were employed as discriminative and contiguous cues (S⁻/CS⁻),respectively. Rats were then subjected to a daily extinction sessions,during which lever presses progressively decreased.

A reinstatement test was conducted by re-exposing them to theconditioned stimuli predictive of ethanol or water availability, but inthe absence of the fluids. Naltrexone (1.0 mg/kg) and pioglitazone wereco-administered 1 hour before the reinstatement test. Experiments wereconducted at the beginning of the dark phase of the light/dark cycle.Animals received all drug treatments according to a counterbalance Latinsquare design and a 3-day interval was allowed between reinstatementsessions. In the reinstatement test, active and inactive lever responseswere recorded.

For yohimbine-induced reinstatement of alcohol seeking, rats reached astable baseline of responding for 10% (v/v) alcohol in 15 days.Following this time period, alcohol self-administration phase extinctiontraining began. During the extinction phase, responding progressivelydecreased. The intraperitoneal administration of the alpha-2adrenoceptor antagonist yohimbine at the dose of 1.25 mg/kgsignificantly reinstated the operant response for alcohol F(1,8)=12.86p<0.01]. As shown by the analysis of variance, pre-treatment withnaltrexone plus pioglitazone significantly reduced the effect ofyohimbine [F(2,8)=5.71, p<0.01] (FIG. 13A). Analysis of inactive leverresponding revealed absence of treatment effects at this lever.

For cue-induced reinstatement of alcohol seeking, msP rats rapidlylearned to discriminate between alcohol or water availability; ratsresponded at a higher level for alcohol. During extinction, leverpressing progressively decreased. In the reinstatement test, the ANOVAshowed that cues had a significant overall effect on alcohol-seeking[F(1,9)=31.83, p<0.01]. A more detailed analysis showed a robustreinstatement of responding under the S⁺/CS⁺ (p<0.01) but not under theS⁻/CS⁻ compared with the last day of extinction. As shown in FIG. 13B,conditioned reinstatement of alcohol-seeking was significantly reducedby co-administration of naltrexone and pioglitazone [F(2,9)=16.58;p<0.01]. Responses at the inactive lever were not influenced by thetreatment (data not shown).

Example 14 Effect of Acute Pioglitazone Plus Fluoxetine Administrationon Voluntary Ethanol Intake

In this experiment, the effect of the co-administration of pioglitazoneand fluoxetine on alcohol consumption was studied to demonstrate thatco-treatment with PPARγ agonists, e.g., TZDs, and antidepressants, e.g.,selective serotonin uptake inhibitors, has synergistic effects onethanol intake inhibition. For this purpose, a low dose of fluoxetine(3.0 mg/kg, OS) that did not reduce ethanol intake in msP rats in apilot study was used. Also, a pioglitazone dose (10 mg/kg, OS) waschosen that does not significantly affect alcohol intake per se.

MsP rats were first trained to drink 10% (w/v) alcohol for 24 hours aday (free choice between water and ethanol). Once a stable ethanoldrinking baseline was reached (6-8 g/kg/day), in a between subjectdesign, msP rats (n=34) were tested for the effect of pioglitazone,fluoxetine or their combination. Rats treated with drug vehicles servedas a control. Before starting the treatment, rats were trained to gavageadministration for three days, during which they received drugs vehicle(distilled water). Pioglitazone and fluoxetine were given twice, at 12hours and 1 hour before access to ethanol. Drinking experiments startedat the beginning of the dark cycle. Alcohol, water, and food intakeswere monitored at 2, 8 and 24 hours after ethanol was made available.

Analysis of variance revealed a significant overall effect of treatment[F(3,30)=5.37 p<0.01] on alcohol intake. As shown in FIG. 14, post-hoctests demonstrated that a low dose of pioglitazone alone or fluoxetinealone did not significantly modify ethanol intake in msP rats. However,co-administration of the two agents resulted in a marked inhibition ofethanol consumption at 2 and 8 hours (p<0.01), as well as at 24 hours(p<0.05). These data suggest that co-administration of the two drugsexert synergistic inhibitory actions on ethanol drinking.

A modest, nonsignificant trend to an increase of food intake wasobserved following drug treatment (data not shown). Water consumptionwas very low and was not modified by drug administration (data notshown).

Example 15 Effect of Acute Pioglitazone Plus Mirtazapine Administrationon Voluntary Ethanol Intake

The effect of the co-administration of pioglitazone and mirtazapine onalcohol consumption was studied to demonstrate that co-treatment withPPARγ agonists and this antidepressant had synergistic effects onethanol intake inhibition. For this purpose, a low dose of mirtazapine(5.0 mg/kg, OS) that did not reduce ethanol intake in msP rats in apilot study was used. Also, a pioglitazone dose (10 mg/kg, OS) waschosen such that it did not significantly affect alcohol intake per se.

MsP rats were first trained to drink 10% (w/v) alcohol for 24 hours aday (free choice between water and ethanol). Once stable ethanoldrinking baseline was reached (6-8 g/kg/day), in a between subjectdesign, msP rats (n=34) were tested for the effect of pioglitazone,mirtazapine or their combination. Rats treated with drug vehicles servedas a control. Before starting the treatment, rats were trained to gavageadministration for three days, during which they received drugs vehicle(distilled water). Pioglitazone and mirtazapine were given twice, at 12hours and 1 hour before access to ethanol. Drinking experiments startedat the beginning of the dark cycle. Alcohol, water and food intakes weremonitored at 2, 8 and 24 hours after ethanol was made available.

Analysis of variance revealed a significant overall effect of treatment[F(3,30)=12.50 p<0.01] on alcohol intake. As shown in FIG. 15, post-hoctests demonstrated that a low dose of pioglitazone alone or mirtazapinealone did not significantly modify ethanol intake in msP rats. However,co-administration of the two agents resulted in a marked inhibition ofethanol consumption at 2 and 8 hours (p<0.05); a significant reductionof ethanol intake at 2 hours was also reported for pioglitazone alone(p<0.05). These data suggest that co-administration of the two drugsexert synergistic inhibitory actions on ethanol drinking.

A nonsignificant trend to an increase of food intake was observedfollowing drug treatments (data not shown). Water consumption was verylow and was not modified by drug administration (data not shown)

Example 16 Effect of Acute Pioglitazone Plus Topiramate Administrationon Voluntary Ethanol Intake

In this experiment, the effect of the co-administration of pioglitazoneand topiramate on alcohol consumption was studied to demonstrate thatco-treatment with PPARγ agonists and this antiepileptic has synergisticeffects on ethanol intake inhibition. For this purpose, a low dose oftopiramate (30.0 mg/kg, OS) that did not reduce ethanol intake in msPrats in a pilot study was used. Also, a pioglitazone dose (10 mg/kg, OS)was chosen such that it did not significantly affect alcohol intake perse.

MsP rats were first trained to drink 10% (w/v) alcohol for 24 hours aday (free choice between water and ethanol). Once stable ethanoldrinking baseline was reached (6-8 g/kg/day), in a between subjectdesign, msP rats (n=34) were tested for the effect of pioglitazone,topiramate or their combination. Rats treated with drug vehicles servedas a control. Before starting the treatment, rats were trained to gavageadministration for three days, during which they received drugs vehicle(distilled water). Pioglitazone and topiramate were given twice, at 12hours and 1 hour before access to ethanol. Drinking experiments startedat the beginning of the dark cycle. Alcohol, water and food intakes weremonitored at 2, 8 and 24 hours after ethanol was made available.

Analysis of variance revealed a significant overall effect of treatment[F(3,30)=4.35 p<0.01] on alcohol intake. As shown in FIG. 16, post-hoctests demonstrated that a low dose of pioglitazone alone or topiramatealone did not significantly modify ethanol intake in msP rats. However,co-administration of the two agents resulted in a marked inhibition ofethanol consumption at 2, 8 and 24 hours (p<0.05); a significantreduction of ethanol intake at 2 hours was also reported for topiramatealone (p<0.05). These data suggest that co-administration of the twodrugs exert synergistic inhibitory actions on ethanol drinking.

A nonsignificant trend to an increase of food intake was observedfollowing drug treatments (data not shown). Water consumption was verylow and was not modified by drug administration (data not shown).

Example 17 Effect of Acute Pioglitazone Plus LevetiracetamAdministration on Voluntary Ethanol Intake

The effect of the co-administration of pioglitazone and levetiracetam onalcohol consumption was studied to demonstrate that co-treatment withPPARγ agonists and this antiepileptic has synergistic effects on ethanolintake inhibition. For this purpose, a low dose of levetiracetam (100.0mg/kg, OS) that did not reduce ethanol intake in msP rats in a pilotstudy was used. Also, a pioglitazone dose (10 mg/kg, OS) was chosen,such that it did not significantly affect alcohol intake per se.

MsP rats were first trained to drink 10% (w/v) alcohol for 24 hours aday (free choice between water and ethanol). Once stable ethanoldrinking baseline was reached (6-8 g/kg/day), in a between subjectdesign, msP rats (n=33) were tested for the effect of pioglitazone,levetiracetam or their combination. Rats treated with drug vehiclesserved as a control. Before starting the treatment, rats were trained togavage administration for three days, during which they received drugsvehicle (distilled water). Pioglitazone and levetiracetam were giventwice, at 12 hours and 1 hour before access to ethanol. Drinkingexperiments started at the beginning of the dark cycle. Alcohol, waterand food intakes were monitored at 2, 8 and 24 hours after ethanol wasmade available.

Analysis of variance revealed a significant overall effect of treatment[F(3,29)=3.76 p<0.05] on alcohol intake. As shown in FIG. 17, post-hoctests demonstrated that a low dose of pioglitazone alone orlevetiracetam alone did not significantly modify ethanol intake in msPrats. Conversely, co-administration of the two agents resulted in amarked inhibition of ethanol consumption at 2 hours (p<0.01), as well asat 8 and 24 hours (p<0.05). These data suggest that co-administration ofthe two drugs exerts synergistic inhibitory actions on ethanol drinking.

Food and water consumption was not modified by drug administration (datanot shown).

Example 18 Effect of Acute Pioglitazone Plus Gabapentin Administrationon Voluntary Ethanol Intake

The effect of the co-administration of pioglitazone and gabapentin onalcohol consumption was studied to demonstrate that co-treatment withPPARγ agonists and this antiepileptic has synergistic effects on ethanolintake inhibition. For this purpose, a low dose of gabapentin (60.0mg/kg, OS) that did not reduce ethanol intake in msP rats in a pilotstudy was used. Also a pioglitazone dose (10 mg/kg, OS) was chosen, suchthat it did not significantly affect alcohol intake per se.

MsP rats were first trained to drink 10% (w/v) alcohol for 24 hours aday (free choice between water and ethanol). Once stable ethanoldrinking baseline was reached (6-8 g/kg/day), in a between subjectdesign, msP rats (n=36) were tested for the effect of pioglitazone,gabapentin or their combination. Rats treated with drug vehicles servedas a control. Before starting the treatment, rats were trained to gavageadministration for three days, during which they received drugs vehicle(distilled water). Pioglitazone and topiraate were given twice, at 12hours and 1 hour before access to ethanol. Drinking experiments startedat the beginning of the dark cycle. Alcohol, water and food intakes weremonitored at 2, 8 and 24 hours after ethanol was made available.

Analysis of variance revealed a significant overall effect of treatment[F(3,7)=3.31 p<0.05] on alcohol intake. As shown in FIG. 18, post-hoctests demonstrated that a low dose of pioglitazone alone or gabapentinalone did not significantly modify ethanol intake in msP rats.Conversely, co-administration of the two agents resulted in a markedinhibition of ethanol consumption at 2 and 8 hours (p<0.05). These datasuggest that co-administration of the two drugs exerts synergisticinhibitory actions on ethanol drinking.

A nonsignificant trend to an increase of food intake was observedfollowing drug treatments (data not shown). Water consumption was verylow and was not modified by drug administration (data not shown).

Example 19 Effect of Acute Pioglitazone Plus Ondansetron Administrationon Voluntary Ethanol Intake

The effect of the co-administration of pioglitazone and ondansetron onalcohol consumption was studied to demonstrate that co-treatment withPPARγ agonists and this serotonin-3 (5-HT3) receptor selectiveantagonist have synergistic effects on ethanol intake inhibition. Forthis purpose, a low dose of ondansetron (1.0 mg/kg, IP) that did notreduce ethanol intake in msP rats in a pilot study was used. Also, apioglitazone dose (10 mg/kg, OS) was chosen, such that it did notsignificantly affect alcohol intake per se.

MsP rats were first trained to drink 10% (w/v) alcohol for 24 hours aday (free choice between water and ethanol). Once stable ethanoldrinking baseline was reached (6-8 g/kg/day), in a between subjectdesign, msP rats (n=36) were tested for the effect of pioglitazone,ondansetron, or their combination. Rats treated with drug vehiclesserved as a control. Before starting the treatment, rats were trained togavage administration for three days, during which they received drugsvehicle (distilled water). Pioglitazone and ondansetron were giventwice, at 12 hours and 1 hour before access to ethanol. Drinkingexperiments started at the beginning of the dark cycle. Alcohol, waterand food intakes were monitored at 2, 8 and 24 hours after ethanol wasmade available.

Analysis of variance revealed a nonsignificant overall effect oftreatment [F(3,32)=2.73 p<0.05], but a significant treatment timeinteraction on alcohol intake was observed [F(6,64)=2.29 p<0.0.5]. Asshown in FIG. 19, post-hoc tests demonstrated that a low dose ofpioglitazone alone or ondansetron alone did not significantly modifyethanol intake in msP rats. However, co-administration of the two agentsresulted in a marked inhibition of ethanol consumption at 24 hours(p<0.05). Water and food consumption was very low and was not modifiedby drug administration (data not shown). These data suggest thatco-administration of the two drugs exerts synergistic inhibitory actionson ethanol drinking.

Example 20 Effect of Acute Pioglitazone Plus Antalarmin Administrationon Voluntary Ethanol Intake

The effect of the co-administration of pioglitazone and antalarmin onalcohol consumption was studied to demonstrate that co-treatment withPPARγ agonists and this corticotrophin releasing factor CRF1 receptorselective antagonist has synergistic effects on ethanol intakeinhibition. For this purpose, a low dose of antalarmin (15.0 mg/kg, IP)that modestly reduced ethanol intake in msP rats in a pilot study wasused. Also, a pioglitazone dose (10 mg/kg, OS) was chosen, such that itdid not significantly affect alcohol intake per se.

MsP rats were first trained to drink 10% (w/v) alcohol for 24 hours aday (free choice between water and ethanol). Once stable ethanoldrinking baseline was reached (6-8 g/kg/day), in a between subjectdesign, msP rats (n=32) were tested for the effect of pioglitazone,antalarmin or their combination. Rats treated with drug vehicles servedas a control. Before starting the treatment, rats were trained to gavageadministration for three days during which they received drugs vehicle(distilled water). Pioglitazone and antalarmin were given twice, at 12hours and 1 hour before access to ethanol. Drinking experiments startedat the beginning of the dark cycle. Alcohol, water and food intakes weremonitored at 2, 8 and 24 hours after ethanol was made available.

Analysis of variance revealed a significant overall effect of treatment[F(3,28)=3.29 p<0.05] on alcohol intake. As shown in FIG. 20, post-hoctests demonstrated that a low dose of pioglitazone alone or antalarminalone did not significantly modify ethanol intake in msP rats. However,co-administration of the two agents resulted in a marked inhibition ofethanol consumption at 8 (p<0.01) and 24 hours (p<0.05); a significantreduction of ethanol intake at 8 hours was also reported for antalarminalone (p<0.05). These data suggest that co-administration of the twodrugs exerts synergistic inhibitory actions on ethanol drinking.

Water and food consumption was not modified by drug administration (datanot shown).

Example 21 Effect of Pioglitazone Administration on Alcohol Withdrawal

The effect of pioglitazone administration on alcohol withdrawal wasdetermined in rats. Male Wistar rats were subjected to a six days ofintermittent alcohol intoxication. During the dark phase, rats received4 oral administration of 2.5-3.0 g/kg of 20% ethanol. The first ethanoldose was given at the beginning of the dark phase. The other 3 dailydoses were administered at intervals of 3 hours. Rats were not injectedduring the light phase of the light/dark cycle. Targeted blood alcohollevels were 250-300 mg/dl. After 6 days of this treatment, rats undergoto spontaneous withdrawal, which generally appears between 8 and 14hours after the last ethanol injection. Pioglitazone (0.0, 10 and 30mg/kg) was administered twice, 12 hours and 1 hour before ratingwithdrawal symptoms. Behavioural signs of withdrawal included: (1)presence of the ventromedial distal flexion response; (2) tailstiffness/rigidity; and (3) tremors (Schulteis et al. 1995). Each signwas rated during a 3-5 min observation period on a scale of 0-2 (Maceyet al., 1996; Schulteis, et al., 1995). All signs were cumulated toyield an overall withdrawal severity score.

Twelve hours after the last ethanol administration, animals treated withpioglitazone vehicle showed marked withdrawal symptoms. The analysis ofvariance showed an overall effect of pioglitazone treatment that reducedtail rigidity [F(4,25)=11.98 p<0.001] (FIG. 21). Post hoc tests revealedthat alcohol withdrawal signs were significantly reduced afteradministration of both 10 mg/kg and 30 mg/kg of pioglitazone, with ahighly significant effect of tail rigidity (p<0.01), tremors (p<0.01),and ventromedial limb retraction (p<0.01). Interestingly, whilemeasuring withdrawal score, two out of the 7 animals of vehicle treatedgroups showed convulsion. Conversely, none of the 12 rats treated withpioglitazone showed seizures. These data suggest that pioglitazone notonly helps to reduce ethanol drinking (see previous experiments), but italso possesses the ability to reduce or control alcohol withdrawalsyndrome and related symptoms, including seizures.

Example 22 Effect of Pioglitazone on Alcohol Abuse in Humans

An observational study of human patients using pioglitazone (Actos®) forthe treatment of diabetes was performed to demonstrate that PPARγagonists, alone or in combination with opioid antagonists, are effectivein reducing ethanol abuse.

A total of 12 patients were enrolled in the study. 4 patients (2 maleand 2 female) received only psychotherapy (Control; CRT); 4 patients(male) received naltrexone 50 mg/day (NTX)+psychotherapy; and 4 patients(3 male and 1 female) received pioglitazone 30 mg/day (Actos®;ACT)+psychotherapy. The patients' ages ranged from 25 to 45 years old.All patients had previous unsuccessful experiences of alcoholdetoxification. No major psychiatric comorbidity was identified. Patienttreated with Actos® were all diagnosed with diabetes.

Patients were instructed to record in a personal logbook the number ofdrinks per day and the time of the day drinks occurred. At the end ofthe study, the logbooks were returned to the clinical personnel whoanalyzed the data. Immediately before beginning treatment and on aweekly basis, patients were interviewed and subjected to the SpielbergerState-Trait Anxiety Inventory (STAI), the Montgomery Asberg DepressionRating Scale (M.A.D.R.S 10 Item) and the Obsessive Compulsive DrinkingScale (OCDS) questioners to score anxiety, depression and alcoholcraving, respectively (Bruno 1989; Janiri, Gobbi et al. 1996) (Cador,Cole et al. 1993; Anton, Moak et al. 1996).

In addition, biochemical parameters to ascertain alcohol detoxificationand to measure recovery of physiological functions (i.e., hepaticfunction) were monitored monthly. Hematological parameters measuredincluded: mean corpuscular volume (MCV); gamma-GT; aspartateaminotransferase (AST); alanine aminotransferase (ALT); andcarbohydrate-deficient transferring (CDT). MCV and CDT are biomarkersfor ethanol consumption, and GGT, ALT and AST are biomarkers for hepaticfunctionality.

Data were analyzed by analysis of variance followed by Newman-Keuls posthoc tests when appropriate.

Statistical analysis revealed an overall significant effect ofpharmacological treatments on the number of daily drinks. Bothnaltrexone and pioglitazone significantly reduced daily ethanol intakeand increased the number of abstinence days. Nonparametric KrustallWallis test showed that naltrexone was more effective than pioglitazoneon the first two weeks of treatment (P<0.05). Over time the effect ofpioglitazone progressively increased and from month 2 week 2 (T2.2) tomonth 2 week 4 (T2.4) it was significantly higher than that ofnaltrexone (p<0.001). The number of abstinence days was significantlydifferent in drug treated patients compared to control. The highesteffect was observed in patients treated with pioglitazone. The number ofabstinence days in the pioglitazone treated group was significantlyhigher to that of naltrexone treated patients during the second month oftherapy (T 2.1, T2.2, T2.3 and T2.4). No changes in daily alcoholconsumption were observed in the group subjected to only psychotherapy.Follow-up evaluation continued for 9 months before interrupting thetherapy. Results showed that all participants except pioglitazonetreated patients dropped out from the treatment.

Blood tests showed that at recruitment all twelve participants hadplasma levels of MCV, CDT, GGT, ALT and AST reflecting a situationcompatible with long term excessive alcohol drinking. However, resultsdemonstrated a rapid normalization of all blood parameters in patientstreated with pioglitazone (ACT), as shown in Table 2.

TABLE 2 Mean value of blood tests T0 T1 = 4 weeks T2 = 8 weeks ACT NTXCTR ACT NTX CTR ACT NTX CTR MCV 102.26 101.96 102.78 99.82 101.96 103.2691.37 97.96 104.87 GGT 192.21 167.38 173.58 86.7 91.35 181.67 38.26 42.9179.47 ALT 51.6 62.7 58.7 45.6 52.8 52 24.9 41.8 55.9 AST 69.2 49.3 82.151.9 41.5 78.4 29.3 38.3 77 CDT 3.2 3.6 3.8 2.9 3.0 3.7 2.1 2.5 3.1The decrease of MCV and CDT indicated that patients' ethanol drinkingprogressively decreased over the two-months of drug treatment. Thedecrease in GGT, ALT and AST reflected normalisation of hepaticfunction. In naltrexone treated patients (NTX), a decrease in MCV andCDT was also observed, but to a lesser extent compared to thepioglitazone group. Hepatic parameters were also ameliorated bynaltrexone, but again the effect of pioglitazone was more pronounced.The Control group that received only psychotherapy did not show anyimprovement during the 2-month treatment.

Statistical analysis revealed an overall effect of treatment for allblood parameters measured (MCV, [F(2,9)=89.7 P<0.0001]; GGT;[F(2,9)=5328 P<0.0001]; ALT [F(2,9)=52.57 P<0.0001]; AST [F(2,9)=771P<0.0001]; CDT [F(2,9)=26.54 P<0.0001]). Post hoc tests revealed thatfor all the five biomarkers a statistical difference (P<0.001) existsbetween controls (psychotherapy alone) and patients treated withnaltrexone (P<0.001) or with pioglitazone (P<0.001). Pioglitazone wasmore effective than naltrexone in reducing the values of MCV (P<0.001),GGT (P<0.001) and ALT (p<0.001). No significant difference betweennaltrexone and pioglitazone were detected for CDT and AST.

Results also showed a progressive decrease in anxiety score duringtreatment. Pioglitazone showed the highest effect, as shown in Table 3and FIG. 30A. In control patients, (psychotherapy alone) anxiety did notdiminish during treatment.

TABLE 3 Anxiety Score obtained using The STAY-Y1 scale (mean scorevalues) ACT NTX CTR T = 0 59 61 63 T = 1.1 58 61 64 T = 1.2 55 59 62 T =1.3 54 53 69 T = 1.4 56 52 65 T = 2.1 49 51 61 T = 2.2 47 53 63 T = 2.343 52 67 T = 2.4 40 51 64 T = 0 corresponds to the beginning of thetreatment; T = 1.1 corresponds to month 1, week 1; T = 1.2 correspondsto month 1, week 2, etc.

The analysis of variance revealed an overall effect of treatment([F(2,9)=142.86 P<0.0001]). Post hoc tests revealed statisticallysignificant difference between controls and patients treated withnaltrexone (P<0.001) or with pioglitazone (P<0.001). Pioglitazone wasmore effective than naltrexone, and a significant difference betweenpioglitazone and naltrexone was also observed (p<0.001)

Results also showed a progressive decrease in obsessive compulsive scorefor alcohol. The effect was extremely robust for pioglitazone, as shownin Table 4 and FIG. 30C. In control patients, OCDS remained atpre-treatment level.

TABLE 4 Obsessive compulsive drinking scale (OCDS) (mean score values)ACT NTX CTR T = 0 50 49 52 T = 1.1 45 47 49 T = 1.2 37 45 48 T = 1.3 3641 49 T = 1.4 34 40 47 T = 2.1 31 41 47 T = 2.2 29 43 49 T = 2.3 28 4250 T = 2.4 28 44 51 T = 0 corresponds to the beginning of the treatment;T = 1.1 corresponds to month 1, week 1; T = 1.2 corresponds to month 1,week 2, etc.

The analysis of variance revealed an overall effect of treatment([F(2,9)=329.27 P<0.0001]). Post hoc tests revealed statisticallysignificant difference between controls and patients treated withnaltrexone (P<0.001) or with pioglitazone (P<0.001). Pioglitazone wasmore effective than naltrexone, and a significant difference betweenpioglitazone and naltrexone was also observed (p<0.001).

The initial Score in the MADRS scale indicated that this patientpopulation did not have severe co-morbid depression. During treatmentwith pioglitazone, the depression score decreased starting from thesecond week of treatment, as shown in Table 5 and FIG. 30B. At week 3,it reached the plateau. However, a floor effect might have contributedto rapid plateau.

TABLE 5 Depression Scale M.A.D.R.S (mean score values) ACT NTX CTR T = 021 19 20 T = 1.1 15 16 18 T = 1.2 13 18 19 T = 1.3 10 16 17 T = 1.4 1117 19 T = 2.1 12 17 21 T = 2.2 13 15 19 T = 2.3 10 18 19 T = 2.4 12 19 T= 0 corresponds to the beginning of the treatment; T = 1.1 correspondsto month 1, week 1; T = 1.2 corresponds to month 1, week 2, etc.

The analysis of variance revealed an overall effect of treatment([F(2,9)=42.12 P<0.0001]). Post hoc tests revealed statisticallysignificant difference between controls and patients treated withpioglitazone (P<0.001) but not naltrexone. Pioglitazone wassignificantly different also from naltrexone (p<0.001)

In summary, the blood parameters determined during the course of thisstudy indicated normalization of different alcohol drinking relatedmarkers in patients treated with pioglitazone or naltrexone. The effectwas more robust with pioglitazone. Patients under psychotherapy alonedid not show improvements during treatment. This indicates that thedifference between Controls and Drug treated patients depended upon thepharmacological intervention.

High comorbidity exists between alcohol abuse, anxiety and depression.The symptoms of these mood-related disorders tend to exacerbate duringearly alcohol detoxification phase, thus contributing to reducedpatients compliance. In this respect, it is highly relevant thatpioglitazone reduces anxiety and depressive symptoms in alcoholicpatients. This could also explain why after two months of drugadministration, all 4 patients under pioglitazone were still intreatment, whereas 2 patients of the control group and 1 of thenaltrexone the group dropped out. It is also highly relevant thatpioglitazone consistently reduced OCDS score. Obsession for alcohol andthe urge to drink (which are measured by OCDS scale) are the majorpredictors of relapse. These data indicate, therefore, that pioglitazonehas anti-relapse properties.

The absence of a placebo treatment in the control (psychotherapy alone)group may have contributed to the high efficacy of drug treatments,since the effect of naltrexone was higher that that normally reported incontrolled randomized clinical trials. However, placebo effect cannotaccount for the difference between pioglitazone and naltrexone efficacy.In fact, in this case, both groups of patients received pharmacologicalmedications in association with psychotherapy. Based on thisconsideration, while it cannot be ruled out that the effect ofpioglitazone could have been over estimated to some extent in thesestudies, it is evident that this drug has a significant efficacy incontrolling alcohol abuse, and its effect may be superior to naltrexone.

Example 23 Effect of Pioglitazone on Cocaine Self-Administration

The ability of pioglitazone to reduce cocaine use was demonstrated in arat model of cocaine addiction. Cocaine hydrochloride (obtained from theNational Institute on Drug Abuse, Bethesda, Md.) was dissolved insterile physiological saline at a concentration of 0.25 mg/0.1 ml. Drugor vehicle solution was infused at a volume of 0.1 ml over 4 s.Pioglitazone obtained from a commercial source was suspended indistilled water, and the resulting suspension was maintained underconstant agitation until administration. Pioglitazone was given orally(OS) via gavage procedure 12 hours and 1 hour before the beginning ofcocaine self-administration.

Male Wistar rats weighing between 180 and 200 g at the time of arrivalin the lab were used. The rats were housed in groups of three in ahumidity- and temperature-controlled (22° C.) vivarium on a 12 h:12 hreverse light/dark cycle (on, 17:00; off, 05:00) with ad libitum accessto food and water. One week after arrival, rats were subjected tosurgery, and a silastic catheter was implanted into the right jugularvein.

Rats (n=6) were trained to self-administer cocaine in 2-h daily sessionson a fixed-ratio 5 schedule of reinforcement, in which each responseresulted in delivery of 0.25 mg/0.1 ml of fluid cocaine solution.Cocaine self-administration training continued until a stable baselineof responding was reached (less than 10% variation for 3 consecutivedays calculated for each single rat). At this point, drug testing begun.

In a within subject counterbalance order (Latin square design), ratswere treated with pioglitazone (0.0, 10.0 or 30.0 mg/kg) given OS 12hours and 1 hour before the beginning of the self-administrationsession. The number of responses to the active and inactive levers wasrecorded. A 3-day interval was allowed between drug testing. Duringthese intervals, cocaine self-administration was continued tore-establish baseline lever responses.

The effect of pioglitazone administration on cocaine self-administrationwas evaluated by mean of a one-way within factor ANOVA followed byNewman-Keuls post hoc test.

Treatment with pioglitazone significantly reduced cocaineself-administration [F(2,5)=13.189 p<0.01]. Post hoc tests revealed asignificant (p<0.01) reduction of cocaine self-administration at both10.0 and 30.0 mg/kg of pioglitazone (FIG. 22A). Responses at the leftinactive lever were very low and were not modified by pioglitazonetreatment (FIG. 22B).

Example 24 Effect of Pioglitazone on Nicotine Use

The ability of PPARγ agonists and antidepressant to reduce nicotine usewas demonstrated in an animal model of nicotine addiction.

Bupropion hydrochloride (Sigma, Milan, Italy) was dissolved in saline.Nicotine tartrate (Sigma, Milan, Italy) was dissolved in isotonic salineat a concentration of 0.03 mg/0.1 ml free base. The pH of the nicotinesolution was adjusted to 7 with dilute NaOH. Drug or vehicle solutionwas infused at a volume of 0.1 ml over 4 s. Pioglitazone was obtainedfrom commercial source; it was suspended in distilled water, and theresulting suspension was maintained under constant agitation untiladministration. Pioglitazone was given orally (OS) via gavage procedureat 12 hours and 1 hour before the beginning of nicotineself-administration.

Male Long Evans rats weighing between 180 and 200 g at the time ofarrival in the lab were used. The rats were housed in groups of three ina humidity- and temperature-controlled (22° C.) vivarium on a 12 h:12 hreverse light/dark cycle (on, 17:00; off, 05:00) with ad libitum accessto food and water. One week after arrival, the rats were subjected tosurgery, and a silastic catheter was implanted into the right jugularvein.

Rats (n=9) were trained for one week to self-administer cocaine in 2-hdaily sessions on a fixed-ratio 5 schedule of reinforcement, in whicheach five response resulted in delivery of 0.25 mg/0.1 ml of fluidcocaine solution. After the successful completion of cocaine training,rats were allowed to self-administer nicotine at the 0.03 mg/kg/infusiondose by switching the delivery of cocaine for the delivery of a nicotineinfusion. Nicotine self-administration training continued until stablebaseline of responding was established (less than 20% variation for 3consecutive days calculated for each single rat). At this point, drugtesting began.

In a within subject counterbalance order (Latin square design), ratswere treated with pioglitazone (0.0 and 30.0 mg/kg) given OS 12 hoursand 1 hour before the beginning of the self-administration session. Thenumber of responses to the active and inactive levers was recorded. A3-day interval was allowed between drug testing. During these intervals,nicotine self-administration was continued to re-establish leverresponses baseline.

The effect of pioglitazone administration on nicotineself-administration was evaluated by mean of a paired t-test.Statistical significance was set at P<0.05

After a few training days, rats acquired robust operant responding fornicotine. As shown in FIG. 23A, treatment with 30 mg/kg pioglitazonesignificantly reduced nicotine self-administration [t_(df8)=−2.70p<0.05]. Responses at the left inactive lever was very low and were notmodified by pioglitazone treatment (FIG. 23B). These results demonstratethat PPARγ agonists are effective in reducing nicotine use.

Example 25 Effect of Pioglitazone and Selected Therapeutic Agents onNicotine Use

The ability of PPARγ agonists in combination with other therapeuticagents, such as bupropion, nicotine replacement formulations,naltrexone, varenicicline, and CB1 receptor antagonist/inverse agonists,e.g., rimonabant, rosonabant, taranabant, and CP-945598, tosynergistically reduce nicotine use is determined in a rat model ofnicotine addiction.

Experiments are conducted using operant self-administration paradigms,essentially as described in Example 23 (see also Bruijnzeel and Markou,2003; Rauhut et al 2003). Briefly, male Wistar rats are implanted with apermanent silastic catheter into the right jugular vein for intravenousnicotine self-administration (0.03 mg/infusion). Using operantself-administration chambers, rats are trained to self-infuse nicotineunder a fixed ratio 5 schedule of reinforcement (five lever presses toobtain one nicotine infusion). Nicotine self-administration training iscontinued until stable baseline of responding is established. At thispoint, drug testing is begun.

In a within subject counterbalance order (Latin square design), rats aretreated with pioglitazone (predicted dose range 5-30.0 mg/kg) or withother PPRγ agonists in combination with bupropion, nicotine (replacementformulations; i.e., nicotine patches), naltrexone, varenicicline, orrimonabant. To evaluate synergism between PPRAγ agonists and theselatter drugs, the lowest effective dose for each of the compounds istested in association with the PPARγ agonist. A dose range for bupropionis 10-100 mg/given OS; a dose range for naltrexone is 0.25-2.5 mg/kggiven IP; a dose range for varenicline is 0.25-2.5 mg/kg given IP; and adose range for rimonabant is (0.1-3.0 mg/kg given IP) (Bruijnzeel andMarkou, 2003; Rauhut et al. 2003; Steensland P et al. 2007; Cohen et al.2005). The number of responses to the active and inactive leversisrecorded. A 3-day interval is allowed between drug testing. During theseintervals, nicotine self-administration is continued to re-establishlever responses baseline.

Data is analyzed by analysis of variance followed by post-hoc tests(Newman-Keuls or Dunnets) where appropriate. Statistical significance isset at P<0.05. It is expected that these experiments will demonstratethat the combination of a PPARγ agonist and any of the listed drugs willact synergistically in reducing nicotine self-administration, therebydemonstrating the efficacy of using PPARγ and any of these drugs totreat addiction.

Example 26 Effect of Pioglitazone and Antidepressants or OpioidAgonist/Antagonist Partial Agonists on Cocaine Use

The ability of PPARγ agonists in combination with antidepressants,bupropion, fluoxetine, or the opioid parial agonist agonist/antagonist,buprenorphine, to synergistically reduce cocaine use is determined in arat model of cocaine addiction.

Experiments are conducted using operant self-administration paradigms asdescribed in Example 23 (see also Glatz et al. 2002; Peltier et al.1993). Briefly, male Wistar rats are implanted with a permanent silasticcatheter into the right jugular vein for intravenous cocaineself-administration (0.25 mg/infusion). Using operantself-administration chambers, rats are trained to self-infuse cocaineunder a fixed ratio 5 schedule of reinforcement (five lever presses toobtain one cocaine infusion). Cocaine self-administration training iscontinued until stable baseline of responding is established. At thispoint, drug testing is begun.

In a within subject counterbalance order (Latin square design), rats aretreated with pioglitazone (predicted dose range 5-30.0 mg/kg) or withanother PPRγ agonist in combination with bupropion, fluoxetine, orbuprenorphine. To evaluate synergism between PPRAγ agonists and theselatter drugs, the lowest effective dose for each of the compound istested in association. A dose range for bupropion is 10.0-100.0 mg/kggiven OS; a dose range for fluoxetine is 3.0-15.0 mg/kg given OS; and adose range for buprenorphine is 0.1-5.0 mg/kg given IP (Glatz et al.2002; Peltier et al. 1993; Sorge et al. 2005). The number of responsesto the active and inactive levers are recorded. A 3-day interval isallowed between drug testing. During these intervals, nicotineself-administration is continued to re-establish lever responsesbaseline.

Data is analyzed by analysis of variance followed by post-hoc tests(Newman-Keuls or Dunnets) where appropriate. Statistical significance isset at P<0.05. It is expected that these experiments will demonstratethat the combination of a PPARγ agonist and any of the listed drugs willact synergistically in reducing cocaine self-administration, therebydemonstrating the efficacy of using PPARγ and any of these drugs totreat addiction.

Example 27 Effect of Pioglitazone on Development of Opiate Addiction

The ability of PPARγ agonists to reduce opiate use and prevent opiateaddiction is determined in a rat model of opiate addiction.

Experiments are conducted using a conditioned place preference apparatusand a well established procedure to study morphine induced conditionedplace preference (Ciccocioppo et al. 2000). Briefly, using a two-chamberplace conditioning apparatus, male Wistar rats are trained to associatemorphine effects to one side of the box and saline to the other side.Multiple groups of rats are used, and the experiment is conducted in abetween subject design. Animals are pretreated with pioglitazone vehiclebefore the injection of morphine vehicle. Control group receive morphineand pioglitazone vehicles in both compartments.

The rats are conditioned during a conditioning phase of six days. Everyother day, for three times, rats receive subcutaneous injections of 3mg/kg of morphine or its vehicle. Pioglitazone (5.0-30.0 mg/kg) isinjected one hour before morphine. During conditioning, the guillotinedoor remains closed, and the rats are confined for 1 h in onecompartment of the box. The day following the last conditioning session,rats are allowed to explore the entire box for 15 min, and the timespent in each compartment is measured.

Place preference score (referred to as Δ time) for each rat is obtainedby subtracting the time spent in the compartment associated withmorphine vehicle to the time spent in the compartment associated tomorphine injections. The Δ time values are submitted to statisticalanalysis. Data is analyzed by analysis of variance followed by post-hoctests (Newman-Keuls or Dunnets) where appropriate. Statisticalsignificance is set at P<0.05.

It is predicted that morphine will elicit a marked conditioned placepreference, and treatment with pioglitazone will reduce the acquisitionof morphine-induced place conditioning (see for review; Sanchis-Seguraand Spanagel 2006) These results will demonstrate the ability of PPARγagonists to prevent the development of addiction to opioids and morespecifically to morphine.

Example 28 Effect of Pioglitazone Administration on Yohimbine-InducedReinstatement of Nicotine Seeking

Stress and anxiety are major factors in resuming nicotine use in formerabstinent users. As described in Examples 5 and 11 for alcohol, the α-2adrenoreceptor antagonist yohimbine was used to resume extinguishednicotine seeking in rats, in order to investigate the effect ofpioglitazone on the reinstatement of drug seeking in rats previouslytrained to nicotine self-administration. Briefly, following acquisitionof a stable baseline of IV nicotine self-administration (30 μg/0.1ml/infusion), male Long Evans rats (n=8) were subjected to an extinctionperiod of 5 days. During extinction, lever presses were no longercontingently associated to nicotine delivery; hence, operant respondingrapidly decreased.

The day after the last extinction session, rats were subjected to thereinstatement test. To evaluate the effect of pioglitazone onyohimbine-induced reinstatement in counterbalanced order (Latin square),12 and 1 hour (9 p.m and 8 a.m) before the beginning of the test, ratswere administered pioglitazone or its vehicle. Yohimbine (2.0 mg/kg/ml)was administered to all animals at 30 min after the second pioglitazoneadministration, which corresponds to 30 min prior to the start of thereinstatement session. Reinstatement experiments and relative drugtreatments were performed every third day. Between reinstatements,extinction baseline was re-established. The number of operant responsesat both active and inactive lever was recorded.

Statistical analysis of variance revealed an overall significant effectof treatment [F (4,7)=12.153; P<0.01]. Post hoc Newman-Keuls test (FIG.24) revealed a significant reinstatement of responding in yohimbinetreated rats compared to extinction (p<0.001). At all doses tested (5.0,10.0 and 30.0 mg/kg), pioglitazone significantly (p<0.001) decreasedyohimbine-induced reinstatement of nicotine seeking. Responses at theinactive lever were not significantly modified by treatments [F(4,7)=2.358; NS]. These results suggest that PPARγ agonists may be usedto treat nicotine addiction.

Example 29 Clinical Evaluation of Pioglitazone as a Treatment forNicotine Addiction

Millions of people are addicted to nicotine worldwide, but despite theenormous health problems associated with tobacco smoking, very fewmedications are available to facilitate smoking cessation. Mosttherapies developed for nicotine addiction have shown only moderatesuccess in reducing smoking and in preventing relapse, leading to a highfailure rate in attempts to quit smoking. Classical testaments includethe use of nicotine replacement products, anti-depressants (e.g.,bupropione (Amfebutamone®, Wellbutrin®, Zyban®)), and behavioraltherapy.

Recently a new medication, namely varenicline (Chantix®), whichselectively targets the alpha4beta2 nicotinic acetylcholine receptorswhere it acts as a partial agonist, has been developed. Clinicalevidence suggests that this agent has an improved efficacy profilecompared to previously existing treatments. Nevertheless, afterapproximately one year from its commercialization, serious concernsabout side effects associated with varenicline treatment are emerging.In particular, positive associations between varenicline treatment,suicidal ideation, paranoia, and irritability have been described (Kohenand Kremen 2007; Morstad, Kutscher et al. 2008).

To provide clinical proof-of-concept of the efficacy of pioglitazone inthe treatment of nicotine addiction, a pilot study in heavy tobaccosmokers was conducted. For this purpose a three-arm study (3-4 patientsper arm) was designed, where one group of subjects was treated withpioglitazone (15-30 mg/daily escalating doses), another group wastreated with varenicline (dose titrated from 0.5 to 2.0 mg/day accordingto manufacturer instruction), and the third group received bupropione(150 mg/kg). Data were recorded for two months, during which patientswere seen by the physician every other week. Patients were instructed torecord in a personal logbook the number of cigarettes per day and thetime of the day smoking occurred. At the end of the study, the logbookswere returned to the clinical personnel who analyzed the data. Everyother week, participants were interviewed and subjected to theSpielberger State-Trait Anxiety Inventory (STAI), the Montgomery AsbergDepression Rating Scale (M.A.D.R.S 10 Item), and to a Visual AnalogicScale (VAS) to measure nicotine craving. During the first month oftreatment, every two weeks, ACTH and cortisol levels were also monitoredto evaluate HPA activation before and during treatment.

At recruitment, all participants completed the eight item FagerströmTolerance Questionnaire (FTQ; Fargestrom Addicitive Bhaviour (1978)) toobtain data on nicotine dependence severity and were interviewed toregister their sociodemographic characteristics. As shown in Table 6,patients were matched for duration of nicotine use and dependence,social status, etc. The Fargestrom scale revealed that all participantswere severe smokers (Table 7).

Results

Daily Smoking:

Statistical analysis (ANOVA) revealed an overall significant effect ofpharmacological treatments on the percent of weekly smoked cigarettes(Table 8). All four patients treated with pioglitazone completed thetreatment. One of the subjects reached complete abstinence, two othersubjects almost reached abstinence (97% inhibition of smoking), and oneshowed a marked reduction (75%) of smoking. The three participantsreceiving varenicline also showed a robust overall smoking reduction(95%), with one of them reaching complete abstinence. One of thepatients treated with bupropione dropped out after four weeks oftreatment. Prior to his dropping out, the inhibition of smoking in thispatient was very modest (20%). The other two buporpione treated patientscompleted the treatment program, and after 10 weeks of drugadministration, smoking was reduced by about 40%. Post hoc testsrevealed a significant difference between pioglitazone and vareniclinecompared to bupropione (p<0.05), while no significant differences wereidentified between pioglitazone and varenicline. Together, these datasuggest that pioglitazone and varenicline have comparable efficacy inlowering smoking, while bupropione is much less effective.

Biochemical Markers:

Blood tests showed that at recruitment all 10 participants hadcomparable plasma ACTH and cortisol levels, which were within a normalrange. Treatments did not affect hormonal levels, suggesting that noneof the drugs under investigation had effects on the stress axis activity(Table 9).

Anxiety:

The analysis of variance revealed a nonsignificant effect treatment([F(2,6)=0.68 NS]) but a significant effect of time ([F(5,10)=15.66P<0.01]), reflecting a progressive decrease in anxiety score overtreatment weeks. STAI score (FIG. 25A) was significantly reduced inpatients treated with pioglitazone and varenicline, but not withbupropione.

Depression:

The MADRS questioner score was low, and was not significantly affectedby drug treatment ([F(2,6)=3.11 NS]). MADRS score remained at the samelevel throughout the 10 observation weeks (FIG. 25B).

Craving:

Results showed a progressive decrease in craving score measured with thevisual analogic craving scale. Anova did not show any significant effectof treatment ([F(2,6)=2.33 NS]), while a significant effect of time([F(5,10)=72.37 P<0.001]) and of treatment×time interaction([F(5,30)=30.63 P<0.001]) was observed. As shown in FIG. 25C, cravingprogressively decreased over treatment. The highest reduction wasobserved in the varenicline and pioglitazone treated groups. Bupropionewas less effective.

TABLE 6 Characteristics of the study participants on admission totreatment. Pioglitazone 15-30 mg Varenicline Bupropione 4 patients 3patients 3 patients Age 49 ± 3.4 52 ± 4.2 46 ± 6.4 Male sex 3 2 3 FemaleSex 1 1 0 Married All All All Education (Years) 9.3 ± 1.5  8.7 ± 2.4 9.3 ± 1.5  Employed All 2 2 Duration of 23 ± 7.8 21 ± 4.7 25 ± 3.7nicotine use Living situation: 100% 100% 100% with family

TABLE 7 Evaluation of nicotine dependence severity using the FargestromScale at recruitment (T = 0). Dependence score: Modest (0-2);Intermediate (3-4); High (5-6); severe (7-10) Pio Patient 1 Patient 2Patient 3 Patient 4 T = 0 5 8 10 9 Var Patient 1 Patient 2 Patient 3 T =0 9 8 9 Bup Patient 1 Patient 2 Patient 3 T = 0 7 10 9 Pioglitazone(Pio); Varenicline (Var); Bupropione (Bup).

TABLE 8 Percent inhibition of smoking recorded every two weeks. T = 0correspond to baseline data expressed as 100% and is a measure ofsmoking before entering the treatment. Patients were then visited after2, 4, 6 8 and 10 weeks of treatment (T = 2-10). Pio Patient 1 Patient 2Patient 3 Patient 4 T = 0 100 100 100 100 T = 2 27 24 25 23 T = 4 49 3944 41 T = 6 57 46 66 53 T = 8 72 68 84 67 T = 10 100 75 98 96 VarPatient 1 Patient 2 Patient 3 T = 0 100 100 100 T = 2 34 22 38 T = 4 4647 54 T = 6 61 63 62 T = 8 80 87 79 T = 10 93 100 94 Bup Patient 1Patient 2 Patient 3 T = 0 100 100 100 T = 2 100 100 100 T = 4 20 18 15 T= 6 28 20 21 T = 8 34 — 34 T = 10 40 — 45 Pioglitazone (Pio);Varenicline (Var); Bupropione (Bup).

TABLE 9 Plasma Adrenocorticotropic Hormone (ACTH) and Cortisol (CORT)levels in patients treated with Pioglitazone (Pio) Varenicline (Var) orbupropione (Bup). ACTH and Cortisol levels are expressed as pg/dl andμg/l, respectively. Blood samples were taken between 6:00 and 10:00 a.m.Patient 1 Patient 2 Patient 3 Patient 4 Pio ACTH CORT ACTH CORT ACTHCORT ACTH CORT T = 0 36 17 43 13 35 19 32 20 T = 2 39 16 41 15 38 20 3918 T = 4 37 17 39 16 41 17 37 21 T = 6 T = 8 T = 10 Patient 1 Patient 2Patient 3 Var ACTH CORT ACTH CORT ACTH CORT T = 0 39 21 41 19 47 17 T =2 36 20 40 17 46 20 T = 4 40 18 38 18 41 24 Patient 1 Patient 2 Patient3 Bup ACTH CORT ACTH CORT ACTH CORT T = 0 38 20 54 21 44 24 T = 2 35 1952 24 41 23 T = 4 37 17 51 29 40 21 Pioglitazone (Pio); Varenicline(Var); Bupropione (Bup)

The studies described herein showed that pioglitazone markedly reducesnicotine consumption and reinstatement of nicotine seeking elicited byadministration of the pharmacological stressor, yohimbine. Importantly,results of proof-of-concept clinical study confirmed this effect ofpioglitazone. Of the four heavy smokers receiving pioglitazone, threereached almost complete abstinence after two months of treatment. Thefourth patient showed a 75% reduction. Psychometric tests revealed thatnone of the patients treated had comorbid anxiety or depression. Duringtreatment, despite drastic reduction of smoking, rebound anxiety ordepression was not observed. Higher efficacy of pioglitazone wasobserved in comparison to bupropione, while a comparable profile ofefficacy was observed with varenicline.

Example 30 Effect of Pioglitazone on Morphine-Induced AnalgesicTolerance

To induce tolerance to morphine-induced analgesia, twice dailyinjections of a constant dose of morphine were administered to mice aspreviously described (Contet et al. 2008; Mamiya et al., 2001). 49 maleCD mice (Charles River, Calco, Italy, weighing 28-30 g at the beginningof the experiment, were employed. All animals were handled for threedays before the beginning of the treatment and behavioral tests.Experimental subjects were housed in common cages in rooms withartificial 12:12 h light/dark cycle (lights off at 9:00 a.m.), withconstant temperature (20-22° C.) and humidity (45-55%). During theexperiments, animals were offered free access to tap water and foodpellets (4RF18, Mucedola, Settimo Milanese, Italy). Experiments wereconducted during the dark phase of the light/dark cycle. All procedureswere conducted in adherence to the European Community Council Directivefor Care and Use of Laboratory Animals.

Mice were divided into 6 groups. Group 1 (n=8) received drug vehicles(veh/veh). Group 2 (n=9) received pioglitazone vehicle plus 30 mg/kgmorphine. Group 3 (n=8) and Group 4 (n=8) received 10 or 30 mg/kg ofpioglitazone followed by morphine vehicle. Group 5 (n=8) and Group 6(n=7) received 10 or 30 mg/kg of pioglitazone followed by morphine.Animals were treated twice daily (between 9:00 and 10:00 a.m. and 9:00and 10:00 p.m.).

Morphine hydrochloride was purchased from Salars (Milano, Italy).Morphine (30 mg/kg) was dissolved in NaCl 9% and was injectedintraperitoneally (IP) twice a day at the indicated doses in a volume of0.2 ml per mice. Pioglitazone was purchased from commercial sources(pharmacy). It was dissolved in distilled water and was administered pero.s. at the doses of 10 mg/kg and 30 mg/kg in a volume of 0.6 ml permice.

Two different tests were used to monitor analgesic responses. Thetail-flick test was performed 45 min after the morning injection ofmorphine, and the tail-immersion test was performed 45 min after theevening injection of morphine. These tests were chosen, because theyinvolve a spinally-mediated reflex response and can be repeated severaltimes on the same animal (Le Bars et al., 2001).

For the tail-flick test, each mouse was gently restrained in a softtissue pocket, and the tail (1 cm from the tip) was exposed to a hotlight beam. Latency for tail-flick was measured with a 6 seconds cut-offtime. For the tail-immersion test, each mouse was restrained in a softtissue pocket, and the distal half of the tail dipped into a water bathset at 52 C.°. Latency for removing the tail from the hot water wasmeasured with a 10 seconds cut-off time.

In the tail-flick test, overall ANOVA revealed a significant effect oftreatment [F (5,43)=44.37: p<0.0001). As shown in FIG. 26 (upper panel),Newman-Keuls test revealed that morphine significantly increased thetime to tail-flick on day 1, 3 and 5 (p<0.01). The analgesic effect ofmorphine progressively decreased, and non significant difference fromcontrols were found on test days 7 and 9. Conversely, in mice treatedwith morphine plus pioglitazone, the difference between treated rats andcontrols remained significant for the whole duration of the experiment.This suggests that the development of morphine tolerance wassubstantially reduced by the combination. Analgesic responses in micetreated with pioglitazone alone did not differ from controls.

In the tail-immersion test, overall ANOVA revealed a significant effectof treatment [F (5.43)=87.89: p<0.0001). As shown in FIG. 26 (lowerpanel), Newman-Keuls test revealed that morphine significantly increasedthe time to tail-flick on day 1, 3, 5, and 7(p<0.01). The analgesiceffect of morphine progressively decreased, and on test day 9, it wasmarginally significant. The combination of morphine with pioglitazoneelicited a very potent analgesic effect that did not decay over time andremained highly significant for the whole duration of drugself-administration. Again, these data suggest that development ofmorphine tolerance was substantially reduced by the combination.

Example 31 Effect of Pioglitazone on Heroin Self-Administration

To test the effect of pioglitazone on heroin acquisition, 20 male Wistarrats (Charles River, Calco, Italy) were employed. At the beginning ofthe experiments, the animals' body weights ranged between 250 and 280 g.Rats were handled once daily for 5 min for one week before the beginningof the experiments, Experimental subjects were housed in common cages inrooms with artificial 12:12 h light/dark cycle (lights off at 9:00a.m.), constant temperature (20-22° C.) and humidity (45-55%). Duringthe experiments, animals were offered free access to tap water and foodpellets (4RF18, Mucedola, Settimo Milanese, Italy). Experiments wereconducted during the dark phase of the light/dark cycle. All procedureswere conducted in adherence to the European Community Council Directivefor Care and Use of Laboratory Animals.

The rats were divided into two groups. The first group (n=10) wastreated twice daily (12 hours and 1 hour prior to the heroin operantsession). The second group (n=10) was administered pioglitazone vehicle.Heroin self-administration sessions took place between 9:00 and 11:00a.m. Sessions consisted of 2 hours heroin self-administration under anFR1 schedule of reinforcement where each lever pressing delivered aninfusion of 0.1 ml of fluid. To avoid heroine overdosing, immediatelyafter lever activation, the cue light above the active lever was on for20 seconds, during which time lever presses did not activate the pump(TO=20 sec).

Heroine hydrochloride was purchased from Salars (Milano, Italy). Heroinewas dissolved in NaCl 9% at a concentration of 10 μg/0.1 ml for infusionand given intravenously (IV). Pioglitazone was purchased from commercialsources (pharmacy). It was dissolved in distilled water and wasadministered per o.s. at the doses of 10 mg/kg and 30 mg/kg in a volumeof 0.6 ml per mice.

Animals were anesthetized by intramuscular injection of 100-150 μl of asolution containing tiletamine cloridrate (58.17 mg/ml) and zolazepamcloridrate (57.5 mg/ml).

For IV surgery, incisions were made to expose the right jugular vein andthe scull, and a catheter made from silicon tubing (I.D.=0.020 inches,O.D.=0.037 inches) was subcutaneously positioned between these twopoints. After insertion into the vein, the proximal end of the catheterwas anchored to the muscles underlying the vein with surgical silk. Thedistal end of the catheter was attached to a stainless-steel cannulabent at a 90° angle. The cannula was inserted in a support made bydental cement on the scull of the animals, fixed with screws and coveredwith a plastic cap. For one week after surgery, rats were daily treatedwith 0.2 ml of the antibiotic Sodium Cefotaxime (262 mg/ml). For all theduration of the experiments, catheters were daily flushed with 0.2-0.3ml of heparinized saline solution.

Body weights were monitored every day, and catheter patency wasconfirmed approximately every 3 days with an injection of 0.2-0.3 ml ofthiopental sodium (250 mg/ml) solution. Patency of the catheter wasassumed if there was an immediate loss of reflexes. Self administrationexperiments began one week after surgery.

The self-administration stations consisted of operant conditioningchambers (Med Associate Inc.) enclosed in sound-attenuating, ventilatedenvironmental cubicles. Each chamber was equipped with two retractablelevers located in the front panel of the chamber. Heroin was deliveredby a plastic tube that was connected with the catheter before thebeginning of the session. An infusion pump was activated by responses onthe right or active lever, while responses on the left or inactive leverwere recorded but did not result in any programmed consequences.Activation of the pump resulted in a delivery of 0.1 ml of fluid. An IBMcompatible computer controlled the delivery of fluids and recording ofthe behavioral data.

In the pioglitazone vehicle treated group, heroin self-administrationprogressively increased over days. Conversely, in rats pre-treated withpioglitazone, operant responding for cocaine remained extremely low.This effect was reflected by a significant overall difference asdemonstrated by Anova [F (1, 18)=18.714: p<0.001). As shown in FIG. 27,statistical analysis showed that pioglitazone significantly decreasedacquisition of heroin self-administration. Post-hoc comparisonsconfirmed a significant difference between control and the pioglitazonetreated rats from day 3 to day 8. Inactive control lever was notaffected by drug treatment [F(1,18)=3.579; p>0.05)].

Opiate drugs are the major pharmacological remedy used for paintreatment. However, it is important to recognize that abuse andaddiction are potential side effects from chronic use of thesecompounds. Examples 30 and 31 demonstrated that the PPARγ agonist,pioglitazone, reduces development of morphine tolerance and prevents theacquisition of opioid addiction (e.g., heroine self-administration).Based on these finding, it is predicted that during chronic use of anopioid agent, the combination with pioglitazone would result in reducedrisk of escalating morphine (or any other opiate agonist) doses andwould prevent the development of opiate addiction.

PPARγ agonists have been shown to also possess intrinsicanti-inflammatory properties and reduce neuropatic pain. Hence, inaddition to reducing morphine tolerance and addiction, they could alsoexpand the analgesic profile of opioids.

Finally, combining the two active ingredients in the same formulationshould prevent the possibility of inappropriate use of the opiateagents. Diversion risk in this case is limited, because as shown by thepresent data, opioid agonists lose their addictive potential whencombined with PPARγ agonists.

Example 32 Effect of Pioglitazone on Acquisition of Food

To test the effect of pioglitazone on food pellets acquisition, threegroups of Wistar rats were used. The first two groups (n=8/group) weretreated twice a day (12 hours and 1 hour prior to the food operantsession) with pioglitazone at 10 and 30 mg, respectively. The thirdgroup (n=8) was administered with drug vehicle. Food self-administrationsessions took place between 9:00 and 10:00 a.m. Pioglitazone treatmentwas continued for the whole acquisition period (14 days). To increaserats' motivation for food pellet self-administration, rats werefood-restricted and maintained at 80% of their normal body weight.Sessions consisted of 30-min food self-administration under an FR1schedule of reinforcement, where each lever pressing delivered 45 mgfood pellets. Immediately after lever activation, the cue light abovethe active lever was turned on for 10 seconds, during which time leverpresses did not activate the feeder (TO=10 sec).

Results showed no effect of treatment [F (2, 21)=0.748: NS]. As shown inFIG. 28, all rats groups rapidly acquired operant responding for foodand no significant differences were observed between pioglitazone andvehicle treated rats. Inactive control lever was also not affected bydrug treatment [F(2,21)=0.793; p>0.05)] (data not shown).

Example 33 Effect of Pioglitazone on Food Self-Administration

To test the effect of pioglitazone on food self-administration, Wistarrats (n=24) were used. The rats were trained to self-administer foodpellets under a fixed ratio FR1 (TO 10 sec) schedule of reinforcementfor 30 min a day. Each lever pressing delivered 45 mg food pellets.During TO, lever presses were recorded but not reinforced with fooddelivery. The rats were trained to food self administer for severaldays, until a stable baseline of reinforcements was established. At thispoint, for four consecutive days (pretreatment), they were subjected tovehicle injection to habituate them to the drug administrationprocedure. At this point, drug pioglitazone treatment (10 and 30mg/kg/ml) was begun. A third group of rats received drug vehicle andserved as a control. Drug treatment was performed every day, twice dailyfor 4 consecutive days. The number of active operant responses at bothactive and inactive levers were recorded.

Results showed that on the first pretreatment day in all groups of rats,food intake was lower than that recorded during the rest of the study,because animals were not familiar with the injection procedure yet. Drugtreatment started when all rats were trained to the administrationprocedure, and statistical evaluation of the results demonstrated noeffect of treatment [F (2, 21)=0.87: NS]. As shown in FIG. 29, all ratsshowed a high rate of operant responding for food, and no differenceswere observed between pioglitazone and vehicle treated rats. Inactivecontrol lever was also not affected by drug treatment (F(2,21)=0.89; NS;data not shown).

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet, areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

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The invention claimed is:
 1. A method of treating or reducing thelikelihood of an addiction, comprising: determining that a subject hasan addiction to an addictive agent or to the practice of an addictive orcompulsive behavior; determining that the subject has (a) undergone aperiod of abstinence from or limited or reduced use of the addictiveagent, or (b) undergone a period of abstinence from or limited orreduced practice of the addictive or compulsive behavior; and providingto the subject an amount of an agonist of a peroxisomeproliferator-activated receptor gamma (PPARγ agonist) effective toreduce the reward action from practice of the addiction, wherein thePPARγ agonist is a thiazolidinedione (TZD) and wherein the PPARγ agonistis effecting for treating or preventing relapse use of the addictiveagent or practice of the addictive or compulsive behavior.
 2. The methodof claim 1, wherein the subject is addicted to an addictive agent. 3.The method of claim 2, wherein the subject is addicted to an addictiveagent selected from the group consisting of: alcohol, nicotine,marijuana, a marijuana derivative, an opioid agonist, a benzodiazepine,a barbiturate, and a psychostimulant.
 4. The method of claim 3, whereinthe addictive agent is nicotine.
 5. The method of claim 3, wherein theaddictive agent is an opioid agonist is selected from the groupconsisting of: morphine, methadone, fentanyl, sufentanil, anddiacetylmorphine (heroin), alfentanil, allylprodine, alphaprodine,anileridine, apomorphine, benzylmorphine, beta-hydroxy 3-methylfentanyl,bezitramide, carfentanil, clonitazene, codeine, desomorphine,dextromoramide, diampromide, dihydrocodeine, dihydroetorphine,dihydromorphine, dimenoxadol, dimepheptanol, dimethylthiambutene,dioxaphetylbutyrate, dipipanone, eptazocine, ethoheptazine,ethylmethylthiambutene, ethylmorphine, etonitazene, etorphine,hydrocodone, hydromorphone, hydroxypethidine, isomethadone,ketobemidone, LMM, levorphanol, levophenacylmorphan, lofentanil,meperidine, metopon, metazocine, methadyl acetate, metapon, myrophine,narceine, nicomorphine, norlevorphanol, normethadone, normorphine,norpipanone, opium, oxycodone, oxymorphone, papaverine, phenadoxone,phenomorphan, phenoperidine, piminodine, piritramide, propheptazine,promedol, properidine, propoxyphene, remifentanil, thebaine, tildine,tramadol, noscapine, nalorphine, naloxone, naltrexone, phenazocine andpropoxyphene.
 6. The method of claim 3, wherein the addictive agent is apsychostimulant selected from the group consisting of cocaine,amphetamine or and an amphetamine derivative.
 7. The method of claim 1,wherein the subject is addicted to an addictive or compulsive behavior.8. The method of claim 7, wherein the addictive or compulsive behavioris selected from the group consisting of: pathological gambling,pathological overeating, pathological use of electronic devices,pathological use of electronic video games, pathological use ofelectronic communication devices, pathological use of cellulartelephones, addiction to pornography, sex addiction, obsessivecompulsive disorder, compulsive spending, anorexia, bulimia,intermittent explosive disorder, kleptomania, pyromania,trichotillomania, compulsive overexercising, and compulsive overworking.9. The method of claim 1, wherein the TZD is selected from the groupconsisting of: pioglitazone, rosiglitazone, ciglitazone, troglitazone,englitazone, rivoglitazone and darglidazone.
 10. The method of claim 9,wherein the TZD is pioglitazone.
 11. The method of claim 1, furthercomprising providing an additional therapeutic agent, wherein each ofthe PPARγ agonist and the additional therapeutic agent contribute to theeffective treatment or prevention of the addiction.
 12. The method ofclaim 11, wherein said additional therapeutic agent is selected from thegroup consisting of: an opioid antagonist, a mixed opioid partialagonist/antagonist, an antidepressant, an antiepileptic, an antiemetic,a corticotrophin-releasing factor-1 (CRF-1) receptor antagonist, aselective serotonin-3 (5-HT3) antagonist, a 5-HT2A/2C antagonist, and acannabinoid-1 (CB1) receptor antagonist.
 13. The method of claim 11,wherein the additional therapeutic agent is an opioid antagonistselected from the group consisting of naltrexone and nalmefene.
 14. Themethod of claim 11, wherein the additional therapeutic agent is anantidepressant selected from the group consisting of fluoxetine,mirtazapine, and bupropion.
 15. The method of claim 11, wherein theadditional therapeutic agent is an antiepileptic selected from the groupconsisting of benzodiazepines, barbituates, valproates, GABA agents,iminostilibenes, hydantoins, NMDA antagonists, sodium channel blockersand succinamides.
 16. The method of claim 11, wherein the additionaltherapeutic agent is a CRF-1 receptor antagonist that is antalarmin. 17.The method of claim 11, wherein the additional therapeutic agent is aselective serotonin-3 (5-HT3) antagonist that is ondansetron.
 18. Themethod of claim 11, wherein the additional therapeutic agent is acannabinoid-1 (CB1) receptor antagonist selected from the groupconsisting of rimonabant and tanarabant.
 19. The method of claim 11,wherein the additional therapeutic agent is a mixed opioidagonist/antagonist that is buprenorphine.
 20. The method of claim 1,wherein the subject previously reduced or eliminated use of theaddictive agent or practice of the addictive or compulsive behaviour inresponse to treatment with an effective amount of an anti-addictiontreatment, and wherein the subject is no longer exposed to an effectiveamount of the anti-addiction treatment.